Not needing to have Microsoft Excel installed on the machine, The Spire.DataExport can create Excel spreadsheet. This sample demonstrates how to add formulas into xls.

private void button1_Click(object sender, EventArgs e)
{
    Spire.DataExport.XLS.CellExport cellExport5
        = new Spire.DataExport.XLS.CellExport();

    cellExport5.ActionAfterExport = Spire.DataExport.Common.ActionType.OpenView;
    cellExport5.ColumnsWidth.AddRange(new object[] {
                                                            "100",
                                                            "200"});
    cellExport5.DataExported = false;
    cellExport5.DataFormats.CultureName = "zh-CN";
    cellExport5.DataFormats.Currency = "￥#,###,##0.00";
    cellExport5.DataFormats.DateTime = "yyyy-M-d H:mm";
    cellExport5.DataFormats.Float = "#,###,##0.00";
    cellExport5.DataFormats.Integer = "#,###,##0";
    cellExport5.DataFormats.Time = "H:mm";
    cellExport5.FileName = "formula.xls";
    cellExport5.SheetOptions.AggregateFormat.Font.Name = "Arial";
    cellExport5.SheetOptions.CustomDataFormat.Font.Name = "Arial";
    cellExport5.SheetOptions.DefaultFont.Name = "Arial";
    cellExport5.SheetOptions.FooterFormat.Font.Name = "Arial";
    cellExport5.SheetOptions.HeaderFormat.Font.Name = "Arial";
    cellExport5.SheetOptions.HyperlinkFormat.Font.Color = Spire.DataExport.XLS.CellColor.Blue;
    cellExport5.SheetOptions.HyperlinkFormat.Font.Name = "Arial";
    cellExport5.SheetOptions.HyperlinkFormat.Font.Underline = Spire.DataExport.XLS.XlsFontUnderline.Single;
    cellExport5.SheetOptions.NoteFormat.Alignment.Horizontal = Spire.DataExport.XLS.HorizontalAlignment.Left;
    cellExport5.SheetOptions.NoteFormat.Alignment.Vertical = Spire.DataExport.XLS.VerticalAlignment.Top;
    cellExport5.SheetOptions.NoteFormat.Font.Bold = true;
    cellExport5.SheetOptions.NoteFormat.Font.Name = "Tahoma";
    cellExport5.SheetOptions.NoteFormat.Font.Size = 8F;
    cellExport5.SheetOptions.TitlesFormat.Font.Bold = true;
    cellExport5.SheetOptions.TitlesFormat.Font.Name = "Arial";

    ushort currentRow = 1;
    string currentFormula = string.Empty;

    Spire.DataExport.XLS.Cell cell = null;

    cellExport5.Cells.Clear();
    cellExport5.SetColumnWidth(1, 32);
    cellExport5.SetColumnWidth(2, 16);
    cellExport5.SetColumnWidth(3, 16);

    cell = cellExport5.AddString(1, currentRow++, "Examples of formulas :");
    cell.Format.Font.Bold = true;
    cell.Format.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightGreen;
    cell.Format.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid;
    cell.Format.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;

    cell = cellExport5.AddString(1, ++currentRow, "Test data:");
    cell.Format.Font.Bold = true;
    cell.Format.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightGreen;
    cell.Format.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid;
    cell.Format.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;

    //test data
    cellExport5.AddNumeric(2, currentRow, 7.3);
    cellExport5.AddNumeric(3, currentRow, 5);
    cellExport5.AddNumeric(4, currentRow, 8.2);
    cellExport5.AddNumeric(5, currentRow, 4);
    cellExport5.AddNumeric(6, currentRow, 3);
    cellExport5.AddNumeric(7, currentRow++, 11.3);


    cell = cellExport5.AddString(1, ++currentRow, "Formulas");
    cell.Format.Font.Bold = true;
    cell.Format.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightGreen;
    cell.Format.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid;
    cell.Format.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;

    cell = cellExport5.AddString(2, currentRow, "Results");
    cell.Format.Font.Bold = true;
    cell.Format.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightGreen;
    cell.Format.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid;
    cell.Format.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;

    //str.
    currentFormula = "=\"hello\"";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow, "=\"hello\"");
    cellExport5.AddFormula(3, currentRow, "=\"" + new string(new char[] { '\u4f60', '\u597d' }) + "\"");



    //int.
    currentFormula = "=300";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow, currentFormula);

    // float
    currentFormula = "=3389.639421";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow, currentFormula);

    //bool.
    currentFormula = "=false";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow, currentFormula);

    currentFormula = "=1+2+3+4+5-6-7+8-9";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow, currentFormula);

    currentFormula = "=33*3/4-2+10";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow, currentFormula);


    // sheet reference
    currentFormula = "=Sheet1!$B$3";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow, currentFormula);

    // sheet area reference
    currentFormula = "=AVERAGE(Sheet1!$D$3:G$3)";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow, currentFormula);

    // Functions
    currentFormula = "=Count(3,5,8,10,2,34)";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);


    currentFormula = "=NOW()";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=SECOND(11)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=MINUTE(12)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=MONTH(9)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=DAY(10)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=TIME(4,5,7)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=DATE(6,4,2)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=RAND()";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=HOUR(12)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=TEXT(\"world\", \"$d\")";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=MOD(5,3)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=WEEKDAY(3)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=YEAR(23)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=NOT(true)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=OR(true)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=AND(TRUE)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=VALUE(30)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=LEN(\"world\")";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=MID(\"world\",4,2)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=ROUND(7,3)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=SIGN(4)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=INT(200)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=ABS(-1.21)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=LN(15)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=EXP(20)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=SQRT(40)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=PI()";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=COS(9)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=SIN(45)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=MAX(10,30)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=MIN(5,7)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=AVERAGE(12,45)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=SUM(18,29)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=IF(4,2,2)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=SUBTOTAL(3,Sheet1!B2:E3)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    cellExport5.SaveToFile();
}

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Dim cellExport5 As Spire.DataExport.XLS.CellExport
    cellExport5 = New Spire.DataExport.XLS.CellExport

    cellExport5.ActionAfterExport = Spire.DataExport.Common.ActionType.OpenView
    cellExport5.ColumnsWidth.AddRange(New Object() {"100", "200"})
    cellExport5.DataExported = False
    cellExport5.DataFormats.CultureName = "zh-CN"
    cellExport5.DataFormats.Currency = "￥#,###,##0.00"
    cellExport5.DataFormats.DateTime = "yyyy-M-d H:mm"
    cellExport5.DataFormats.Float = "#,###,##0.00"
    cellExport5.DataFormats.Integer = "#,###,##0"
    cellExport5.DataFormats.Time = "H:mm"
    cellExport5.FileName = "formula.xls"
    cellExport5.SheetOptions.AggregateFormat.Font.Name = "Arial"
    cellExport5.SheetOptions.CustomDataFormat.Font.Name = "Arial"
    cellExport5.SheetOptions.DefaultFont.Name = "Arial"
    cellExport5.SheetOptions.FooterFormat.Font.Name = "Arial"
    cellExport5.SheetOptions.HeaderFormat.Font.Name = "Arial"
    cellExport5.SheetOptions.HyperlinkFormat.Font.Color = Spire.DataExport.XLS.CellColor.Blue
    cellExport5.SheetOptions.HyperlinkFormat.Font.Name = "Arial"
    cellExport5.SheetOptions.HyperlinkFormat.Font.Underline = Spire.DataExport.XLS.XlsFontUnderline.Single
    cellExport5.SheetOptions.NoteFormat.Alignment.Horizontal = Spire.DataExport.XLS.HorizontalAlignment.Left
    cellExport5.SheetOptions.NoteFormat.Alignment.Vertical = Spire.DataExport.XLS.VerticalAlignment.Top
    cellExport5.SheetOptions.NoteFormat.Font.Bold = True
    cellExport5.SheetOptions.NoteFormat.Font.Name = "Tahoma"
    cellExport5.SheetOptions.NoteFormat.Font.Size = 8.0!
    cellExport5.SheetOptions.TitlesFormat.Font.Bold = True
    cellExport5.SheetOptions.TitlesFormat.Font.Name = "Arial"

    Dim currentRow As Integer = 1
    Dim firstCol As UInt16 = Convert.ToUInt16(1)
    Dim secondCol As UInt16 = Convert.ToUInt16(2)
    Dim currentFormula As String = String.Empty

    Dim cell As cell = Nothing

    cellExport5.Cells.Clear()
    cellExport5.SetColumnWidth(System.Convert.ToUInt16(1), System.Convert.ToUInt16(32))
    cellExport5.SetColumnWidth(System.Convert.ToUInt16(2), System.Convert.ToUInt16(16))
    cellExport5.SetColumnWidth(System.Convert.ToUInt16(3), System.Convert.ToUInt16(16))

    cell = cellExport5.AddString(System.Convert.ToUInt16(1), System.Convert.ToUInt16(currentRow), "Examples of formulas :")
    currentRow += 1
    cell.Format.Font.Bold = True
    cell.Format.FillStyle.Background = CellColor.LightGreen
    cell.Format.FillStyle.Pattern = Pattern.Solid
    cell.Format.Borders.Bottom.Style = CellBorderStyle.Medium

    cell = cellExport5.AddString(System.Convert.ToUInt16(1), System.Convert.ToUInt16(currentRow), "Test data:")
    currentRow += 1
    cell.Format.Font.Bold = True
    cell.Format.FillStyle.Background = CellColor.LightGreen
    cell.Format.FillStyle.Pattern = Pattern.Solid
    cell.Format.Borders.Bottom.Style = CellBorderStyle.Medium

    'test data
    cellExport5.AddNumeric(System.Convert.ToUInt16(2), System.Convert.ToUInt16(currentRow), 7.3)
    cellExport5.AddNumeric(System.Convert.ToUInt16(3), System.Convert.ToUInt16(currentRow), 5)
    cellExport5.AddNumeric(System.Convert.ToUInt16(4), System.Convert.ToUInt16(currentRow), 8.2)
    cellExport5.AddNumeric(System.Convert.ToUInt16(5), System.Convert.ToUInt16(currentRow), 4)
    cellExport5.AddNumeric(System.Convert.ToUInt16(6), System.Convert.ToUInt16(currentRow), 3)
    cellExport5.AddNumeric(System.Convert.ToUInt16(7), System.Convert.ToUInt16(currentRow), 11.3)
    currentRow += 1
    currentRow += 1


    cell = cellExport5.AddString(Convert.ToUInt16(1), Convert.ToUInt16(currentRow), "Formulas")
    cell.Format.Font.Bold = True
    cell.Format.FillStyle.Background = CellColor.LightGreen
    cell.Format.FillStyle.Pattern = Pattern.Solid
    cell.Format.Borders.Bottom.Style = CellBorderStyle.Medium

    cell = cellExport5.AddString(secondCol, Convert.ToUInt16(currentRow), "Results")
    currentRow += 1
    cell.Format.Font.Bold = True
    cell.Format.FillStyle.Background = CellColor.LightGreen
    cell.Format.FillStyle.Pattern = Pattern.Solid
    cell.Format.Borders.Bottom.Style = CellBorderStyle.Medium

    'str.
    currentFormula = "=""hello"""
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), "=""hello""")
    cellExport5.AddFormula(Convert.ToUInt16(3), Convert.ToUInt16(currentRow), "=""" & ChrW(20320) & ChrW(22909) + """")
    currentRow += 1



    'int.
    currentFormula = "=300"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    ' float
    currentFormula = "=3389.639421"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1


    'bool.
    currentFormula = "=false"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=1+2+3+4+5-6-7+8-9"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=33*3/4-2+10"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    ' sheet reference
    currentFormula = "=Sheet1!$B$3"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    ' sheet area reference
    currentFormula = "=AVERAGE(Sheet1!$D$3:G$3)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    ' Functions
    currentFormula = "=Count(3,5,8,10,2,34)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1


    currentFormula = "=NOW()"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=SECOND(11)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=MINUTE(12)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=MONTH(9)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=DAY(10)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=TIME(4,5,7)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=DATE(6,4,2)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=RAND()"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=HOUR(12)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=TEXT(""world"", ""$d"")"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=MOD(5,3)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=WEEKDAY(3)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=YEAR(23)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=NOT(true)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=OR(true)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=AND(TRUE)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=VALUE(30)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=LEN(""world"")"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=MID(""world"",4,2)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=ROUND(7,3)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=SIGN(4)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=INT(200)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=ABS(-1.21)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=LN(15)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=EXP(20)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=SQRT(40)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=PI()"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=COS(9)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=SIN(45)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=MAX(10,30)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=MIN(5,7)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=AVERAGE(12,45)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=SUM(18,29)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=IF(4,2,2)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=SUBTOTAL(3,Sheet1!B2:E3)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1
    cellExport5.SaveToFile()
End Sub

How to export multiple data tables to different worksheets.

private void button1_Click(object sender, EventArgs e)
{
    System.Data.OleDb.OleDbConnection oleDbConnection1
         = new System.Data.OleDb.OleDbConnection();
    oleDbConnection1.ConnectionString
        = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=..\..\..\..\Database\demo.mdb";

    System.Data.OleDb.OleDbCommand oleDbCommand1
        = new System.Data.OleDb.OleDbCommand();
    oleDbCommand1.CommandText = "select * from parts";
    oleDbCommand1.Connection = oleDbConnection1;

    System.Data.OleDb.OleDbCommand oleDbCommand2
        = new System.Data.OleDb.OleDbCommand();
    oleDbCommand2.CommandText = "select * from country";
    oleDbCommand2.Connection = oleDbConnection1;

    Spire.DataExport.XLS.CellExport cellExport1
        = new Spire.DataExport.XLS.CellExport();
    Spire.DataExport.XLS.WorkSheet workSheet1 = new Spire.DataExport.XLS.WorkSheet();
    Spire.DataExport.XLS.StripStyle stripStyle1 = new Spire.DataExport.XLS.StripStyle();
    Spire.DataExport.XLS.StripStyle stripStyle2 = new Spire.DataExport.XLS.StripStyle();
    Spire.DataExport.XLS.WorkSheet workSheet2 = new Spire.DataExport.XLS.WorkSheet();
    Spire.DataExport.XLS.StripStyle stripStyle3 = new Spire.DataExport.XLS.StripStyle();
    Spire.DataExport.XLS.StripStyle stripStyle4 = new Spire.DataExport.XLS.StripStyle();

    cellExport1.ActionAfterExport = Spire.DataExport.Common.ActionType.OpenView;
    cellExport1.AutoFitColWidth = true;
    cellExport1.AutoFormula = true;
    cellExport1.DataFormats.CultureName = "zh-CN";
    cellExport1.DataFormats.Currency = "$#,###,##0.00";
    cellExport1.DataFormats.DateTime = "yyyy-M-d H:mm";
    cellExport1.DataFormats.Float = "#,###,##0.00";
    cellExport1.DataFormats.Integer = "#,###,##0";
    cellExport1.DataFormats.Time = "H:mm";
    cellExport1.FileName = "Sheets.xls";
    cellExport1.SheetOptions.AggregateFormat.Font.Name = "Arial";
    cellExport1.SheetOptions.CustomDataFormat.Font.Name = "Arial";
    cellExport1.SheetOptions.DefaultFont.Name = "Arial";
    cellExport1.SheetOptions.FooterFormat.Font.Name = "Arial";
    cellExport1.SheetOptions.HeaderFormat.Font.Name = "Arial";
    cellExport1.SheetOptions.HyperlinkFormat.Font.Color = Spire.DataExport.XLS.CellColor.Blue;
    cellExport1.SheetOptions.HyperlinkFormat.Font.Name = "Arial";
    cellExport1.SheetOptions.HyperlinkFormat.Font.Underline = Spire.DataExport.XLS.XlsFontUnderline.Single;
    cellExport1.SheetOptions.NoteFormat.Alignment.Horizontal = Spire.DataExport.XLS.HorizontalAlignment.Left;
    cellExport1.SheetOptions.NoteFormat.Alignment.Vertical = Spire.DataExport.XLS.VerticalAlignment.Top;
    cellExport1.SheetOptions.NoteFormat.Font.Bold = true;
    cellExport1.SheetOptions.NoteFormat.Font.Name = "Tahoma";
    cellExport1.SheetOptions.NoteFormat.Font.Size = 8F;
    cellExport1.SheetOptions.TitlesFormat.Font.Bold = true;
    cellExport1.SheetOptions.TitlesFormat.Font.Name = "Arial";
    workSheet1.AutoFitColWidth = true;
    workSheet1.FormatsExport.CultureName = "zh-CN";
    workSheet1.FormatsExport.Currency = "￥#,###,##0.00";
    workSheet1.FormatsExport.DateTime = "yyyy-M-d H:mm";
    workSheet1.FormatsExport.Float = "#,###,##0.00";
    workSheet1.FormatsExport.Integer = "#,###,##0";
    workSheet1.FormatsExport.Time = "H:mm";
    stripStyle1.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    stripStyle1.Borders.Left.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    stripStyle1.Borders.Right.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    stripStyle1.Borders.Top.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    stripStyle1.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightGreen;
    stripStyle1.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid;
    stripStyle1.Font.Name = "Arial";
    stripStyle2.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    stripStyle2.Borders.Left.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    stripStyle2.Borders.Right.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    stripStyle2.Borders.Top.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    stripStyle2.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightTurquoise;
    stripStyle2.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid;
    stripStyle2.Font.Name = "Arial";
    workSheet1.ItemStyles.Add(stripStyle1);
    workSheet1.ItemStyles.Add(stripStyle2);
    workSheet1.ItemType = Spire.DataExport.XLS.CellItemType.Col;
    workSheet1.Options.AggregateFormat.Font.Name = "Arial";
    workSheet1.Options.CustomDataFormat.Font.Name = "Arial";
    workSheet1.Options.DefaultFont.Name = "Arial";
    workSheet1.Options.FooterFormat.Font.Name = "Arial";
    workSheet1.Options.HeaderFormat.Font.Bold = true;
    workSheet1.Options.HeaderFormat.Font.Color = Spire.DataExport.XLS.CellColor.Blue;
    workSheet1.Options.HeaderFormat.Font.Name = "Arial";
    workSheet1.Options.HyperlinkFormat.Font.Color = Spire.DataExport.XLS.CellColor.Blue;
    workSheet1.Options.HyperlinkFormat.Font.Name = "Arial";
    workSheet1.Options.HyperlinkFormat.Font.Underline = Spire.DataExport.XLS.XlsFontUnderline.Single;
    workSheet1.Options.NoteFormat.Alignment.Horizontal = Spire.DataExport.XLS.HorizontalAlignment.Left;
    workSheet1.Options.NoteFormat.Alignment.Vertical = Spire.DataExport.XLS.VerticalAlignment.Top;
    workSheet1.Options.NoteFormat.Font.Bold = true;
    workSheet1.Options.NoteFormat.Font.Name = "Tahoma";
    workSheet1.Options.NoteFormat.Font.Size = 8F;
    workSheet1.Options.TitlesFormat.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    workSheet1.Options.TitlesFormat.Borders.Left.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    workSheet1.Options.TitlesFormat.Borders.Right.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    workSheet1.Options.TitlesFormat.Borders.Top.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    workSheet1.Options.TitlesFormat.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightYellow;
    workSheet1.Options.TitlesFormat.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid;
    workSheet1.Options.TitlesFormat.Font.Bold = true;
    workSheet1.Options.TitlesFormat.Font.Name = "Arial";
    workSheet1.SheetName = "parts";
    workSheet1.SQLCommand = oleDbCommand1;
    workSheet1.StartDataCol = ((System.Byte)(0));
    workSheet2.AutoFitColWidth = true;
    workSheet2.FormatsExport.CultureName = "zh-CN";
    workSheet2.FormatsExport.Currency = "￥#,###,##0.00";
    workSheet2.FormatsExport.DateTime = "yyyy-M-d H:mm";
    workSheet2.FormatsExport.Float = "#,###,##0.00";
    workSheet2.FormatsExport.Integer = "#,###,##0";
    workSheet2.FormatsExport.Time = "H:mm";
    stripStyle3.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    stripStyle3.Borders.Left.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    stripStyle3.Borders.Right.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    stripStyle3.Borders.Top.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    stripStyle3.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightGreen;
    stripStyle3.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid;
    stripStyle3.Font.Name = "Arial";
    stripStyle4.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    stripStyle4.Borders.Left.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    stripStyle4.Borders.Right.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    stripStyle4.Borders.Top.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    stripStyle4.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightTurquoise;
    stripStyle4.FillStyle.Foreground = Spire.DataExport.XLS.CellColor.White;
    stripStyle4.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid;
    stripStyle4.Font.Name = "Arial";
    workSheet2.ItemStyles.Add(stripStyle3);
    workSheet2.ItemStyles.Add(stripStyle4);
    workSheet2.ItemType = Spire.DataExport.XLS.CellItemType.Col;
    workSheet2.Options.AggregateFormat.Font.Name = "Arial";
    workSheet2.Options.CustomDataFormat.Font.Name = "Arial";
    workSheet2.Options.DefaultFont.Name = "Arial";
    workSheet2.Options.FooterFormat.Font.Color = Spire.DataExport.XLS.CellColor.Blue;
    workSheet2.Options.FooterFormat.Font.Name = "Arial";
    workSheet2.Options.HeaderFormat.Font.Bold = true;
    workSheet2.Options.HeaderFormat.Font.Color = Spire.DataExport.XLS.CellColor.Blue;
    workSheet2.Options.HeaderFormat.Font.Name = "Arial";
    workSheet2.Options.HyperlinkFormat.Font.Color = Spire.DataExport.XLS.CellColor.Blue;
    workSheet2.Options.HyperlinkFormat.Font.Name = "Arial";
    workSheet2.Options.HyperlinkFormat.Font.Underline = Spire.DataExport.XLS.XlsFontUnderline.Single;
    workSheet2.Options.NoteFormat.Alignment.Horizontal = Spire.DataExport.XLS.HorizontalAlignment.Left;
    workSheet2.Options.NoteFormat.Alignment.Vertical = Spire.DataExport.XLS.VerticalAlignment.Top;
    workSheet2.Options.NoteFormat.Font.Bold = true;
    workSheet2.Options.NoteFormat.Font.Name = "Tahoma";
    workSheet2.Options.NoteFormat.Font.Size = 8F;
    workSheet2.Options.TitlesFormat.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    workSheet2.Options.TitlesFormat.Borders.Left.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    workSheet2.Options.TitlesFormat.Borders.Right.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    workSheet2.Options.TitlesFormat.Borders.Top.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;
    workSheet2.Options.TitlesFormat.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightYellow;
    workSheet2.Options.TitlesFormat.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid;
    workSheet2.Options.TitlesFormat.Font.Bold = true;
    workSheet2.Options.TitlesFormat.Font.Name = "Arial";
    workSheet2.SheetName = "country";
    workSheet2.SQLCommand = oleDbCommand2;
    workSheet2.StartDataCol = ((System.Byte)(0));
    cellExport1.Sheets.Add(workSheet1);
    cellExport1.Sheets.Add(workSheet2);
    cellExport1.SQLCommand = oleDbCommand1;
    cellExport1.GetDataParams += new Spire.DataExport.Delegates.DataParamsEventHandler(cellExport1_GetDataParams);

    oleDbConnection1.Open();
    try
    {
        cellExport1.SaveToFile();
    }
    finally
    {
        oleDbConnection1.Close();
    }
}

private void cellExport1_GetDataParams(object sender, Spire.DataExport.EventArgs.DataParamsEventArgs e)
{
    if ((e.Sheet == 0) && (e.Col == 6))
    {
        e.FormatText = (sender as Spire.DataExport.XLS.WorkSheet).ExportCell.DataFormats.Currency;
    }
}

Private WithEvents cellExport1 As Spire.DataExport.XLS.CellExport
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Dim oleDbConnection1 As System.Data.OleDb.OleDbConnection
    oleDbConnection1 = New System.Data.OleDb.OleDbConnection
    oleDbConnection1.ConnectionString = _
        "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=..\..\..\..\Database\demo.mdb"


    Dim oleDbCommand1 As System.Data.OleDb.OleDbCommand
    oleDbCommand1 = New System.Data.OleDb.OleDbCommand
    oleDbCommand1.CommandText = "select * from parts"
    oleDbCommand1.Connection = oleDbConnection1

    Dim oleDbCommand2 As System.Data.OleDb.OleDbCommand
    oleDbCommand2 = New System.Data.OleDb.OleDbCommand
    oleDbCommand2.CommandText = "select * from country"
    oleDbCommand2.Connection = oleDbConnection1

    Dim WorkSheet1 As Spire.DataExport.XLS.WorkSheet = New Spire.DataExport.XLS.WorkSheet
    Dim StripStyle1 As Spire.DataExport.XLS.StripStyle = New Spire.DataExport.XLS.StripStyle
    Dim StripStyle2 As Spire.DataExport.XLS.StripStyle = New Spire.DataExport.XLS.StripStyle
    Dim WorkSheet2 As Spire.DataExport.XLS.WorkSheet = New Spire.DataExport.XLS.WorkSheet
    Dim StripStyle3 As Spire.DataExport.XLS.StripStyle = New Spire.DataExport.XLS.StripStyle
    Dim StripStyle4 As Spire.DataExport.XLS.StripStyle = New Spire.DataExport.XLS.StripStyle

    cellExport1 = New Spire.DataExport.XLS.CellExport
    cellExport1.ActionAfterExport = Spire.DataExport.Common.ActionType.OpenView
    cellExport1.AutoFitColWidth = True
    cellExport1.AutoFormula = True
    cellExport1.DataFormats.CultureName = "zh-CN"
    cellExport1.DataFormats.Currency = "$#,###,##0.00"
    cellExport1.DataFormats.DateTime = "yyyy-M-d H:mm"
    cellExport1.DataFormats.Float = "#,###,##0.00"
    cellExport1.DataFormats.Integer = "#,###,##0"
    cellExport1.DataFormats.Time = "H:mm"
    cellExport1.FileName = "Sheets.xls"
    cellExport1.SheetOptions.AggregateFormat.Font.Name = "Arial"
    cellExport1.SheetOptions.CustomDataFormat.Font.Name = "Arial"
    cellExport1.SheetOptions.DefaultFont.Name = "Arial"
    cellExport1.SheetOptions.FooterFormat.Font.Name = "Arial"
    cellExport1.SheetOptions.HeaderFormat.Font.Name = "Arial"
    cellExport1.SheetOptions.HyperlinkFormat.Font.Color = Spire.DataExport.XLS.CellColor.Blue
    cellExport1.SheetOptions.HyperlinkFormat.Font.Name = "Arial"
    cellExport1.SheetOptions.HyperlinkFormat.Font.Underline = Spire.DataExport.XLS.XlsFontUnderline.Single
    cellExport1.SheetOptions.NoteFormat.Alignment.Horizontal = Spire.DataExport.XLS.HorizontalAlignment.Left
    cellExport1.SheetOptions.NoteFormat.Alignment.Vertical = Spire.DataExport.XLS.VerticalAlignment.Top
    cellExport1.SheetOptions.NoteFormat.Font.Bold = True
    cellExport1.SheetOptions.NoteFormat.Font.Name = "Tahoma"
    cellExport1.SheetOptions.NoteFormat.Font.Size = 8.0!
    cellExport1.SheetOptions.TitlesFormat.Font.Bold = True
    cellExport1.SheetOptions.TitlesFormat.Font.Name = "Arial"
    WorkSheet1.AutoFitColWidth = True
    WorkSheet1.FormatsExport.CultureName = "zh-CN"
    WorkSheet1.FormatsExport.Currency = "￥#,###,##0.00"
    WorkSheet1.FormatsExport.DateTime = "yyyy-M-d H:mm"
    WorkSheet1.FormatsExport.Float = "#,###,##0.00"
    WorkSheet1.FormatsExport.Integer = "#,###,##0"
    WorkSheet1.FormatsExport.Time = "H:mm"
    StripStyle1.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    StripStyle1.Borders.Left.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    StripStyle1.Borders.Right.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    StripStyle1.Borders.Top.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    StripStyle1.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightGreen
    StripStyle1.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid
    StripStyle1.Font.Name = "Arial"
    StripStyle2.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    StripStyle2.Borders.Left.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    StripStyle2.Borders.Right.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    StripStyle2.Borders.Top.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    StripStyle2.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightTurquoise
    StripStyle2.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid
    StripStyle2.Font.Name = "Arial"
    WorkSheet1.ItemStyles.Add(StripStyle1)
    WorkSheet1.ItemStyles.Add(StripStyle2)
    WorkSheet1.ItemType = Spire.DataExport.XLS.CellItemType.Col
    WorkSheet1.Options.AggregateFormat.Font.Name = "Arial"
    WorkSheet1.Options.CustomDataFormat.Font.Name = "Arial"
    WorkSheet1.Options.DefaultFont.Name = "Arial"
    WorkSheet1.Options.FooterFormat.Font.Name = "Arial"
    WorkSheet1.Options.HeaderFormat.Font.Bold = True
    WorkSheet1.Options.HeaderFormat.Font.Color = Spire.DataExport.XLS.CellColor.Blue
    WorkSheet1.Options.HeaderFormat.Font.Name = "Arial"
    WorkSheet1.Options.HyperlinkFormat.Font.Color = Spire.DataExport.XLS.CellColor.Blue
    WorkSheet1.Options.HyperlinkFormat.Font.Name = "Arial"
    WorkSheet1.Options.HyperlinkFormat.Font.Underline = Spire.DataExport.XLS.XlsFontUnderline.Single
    WorkSheet1.Options.NoteFormat.Alignment.Horizontal = Spire.DataExport.XLS.HorizontalAlignment.Left
    WorkSheet1.Options.NoteFormat.Alignment.Vertical = Spire.DataExport.XLS.VerticalAlignment.Top
    WorkSheet1.Options.NoteFormat.Font.Bold = True
    WorkSheet1.Options.NoteFormat.Font.Name = "Tahoma"
    WorkSheet1.Options.NoteFormat.Font.Size = 8.0!
    WorkSheet1.Options.TitlesFormat.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    WorkSheet1.Options.TitlesFormat.Borders.Left.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    WorkSheet1.Options.TitlesFormat.Borders.Right.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    WorkSheet1.Options.TitlesFormat.Borders.Top.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    WorkSheet1.Options.TitlesFormat.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightYellow
    WorkSheet1.Options.TitlesFormat.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid
    WorkSheet1.Options.TitlesFormat.Font.Bold = True
    WorkSheet1.Options.TitlesFormat.Font.Name = "Arial"
    WorkSheet1.SheetName = "parts"
    WorkSheet1.SQLCommand = oleDbCommand1
    WorkSheet1.StartDataCol = CType(0, Byte)
    WorkSheet2.AutoFitColWidth = True
    WorkSheet2.FormatsExport.CultureName = "zh-CN"
    WorkSheet2.FormatsExport.Currency = "￥#,###,##0.00"
    WorkSheet2.FormatsExport.DateTime = "yyyy-M-d H:mm"
    WorkSheet2.FormatsExport.Float = "#,###,##0.00"
    WorkSheet2.FormatsExport.Integer = "#,###,##0"
    WorkSheet2.FormatsExport.Time = "H:mm"
    StripStyle3.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    StripStyle3.Borders.Left.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    StripStyle3.Borders.Right.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    StripStyle3.Borders.Top.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    StripStyle3.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightGreen
    StripStyle3.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid
    StripStyle3.Font.Name = "Arial"
    StripStyle4.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    StripStyle4.Borders.Left.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    StripStyle4.Borders.Right.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    StripStyle4.Borders.Top.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    StripStyle4.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightTurquoise
    StripStyle4.FillStyle.Foreground = Spire.DataExport.XLS.CellColor.White
    StripStyle4.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid
    StripStyle4.Font.Name = "Arial"
    WorkSheet2.ItemStyles.Add(StripStyle3)
    WorkSheet2.ItemStyles.Add(StripStyle4)
    WorkSheet2.ItemType = Spire.DataExport.XLS.CellItemType.Col
    WorkSheet2.Options.AggregateFormat.Font.Name = "Arial"
    WorkSheet2.Options.CustomDataFormat.Font.Name = "Arial"
    WorkSheet2.Options.DefaultFont.Name = "Arial"
    WorkSheet2.Options.FooterFormat.Font.Color = Spire.DataExport.XLS.CellColor.Blue
    WorkSheet2.Options.FooterFormat.Font.Name = "Arial"
    WorkSheet2.Options.HeaderFormat.Font.Bold = True
    WorkSheet2.Options.HeaderFormat.Font.Color = Spire.DataExport.XLS.CellColor.Blue
    WorkSheet2.Options.HeaderFormat.Font.Name = "Arial"
    WorkSheet2.Options.HyperlinkFormat.Font.Color = Spire.DataExport.XLS.CellColor.Blue
    WorkSheet2.Options.HyperlinkFormat.Font.Name = "Arial"
    WorkSheet2.Options.HyperlinkFormat.Font.Underline = Spire.DataExport.XLS.XlsFontUnderline.Single
    WorkSheet2.Options.NoteFormat.Alignment.Horizontal = Spire.DataExport.XLS.HorizontalAlignment.Left
    WorkSheet2.Options.NoteFormat.Alignment.Vertical = Spire.DataExport.XLS.VerticalAlignment.Top
    WorkSheet2.Options.NoteFormat.Font.Bold = True
    WorkSheet2.Options.NoteFormat.Font.Name = "Tahoma"
    WorkSheet2.Options.NoteFormat.Font.Size = 8.0!
    WorkSheet2.Options.TitlesFormat.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    WorkSheet2.Options.TitlesFormat.Borders.Left.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    WorkSheet2.Options.TitlesFormat.Borders.Right.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    WorkSheet2.Options.TitlesFormat.Borders.Top.Style = Spire.DataExport.XLS.CellBorderStyle.Medium
    WorkSheet2.Options.TitlesFormat.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightYellow
    WorkSheet2.Options.TitlesFormat.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid
    WorkSheet2.Options.TitlesFormat.Font.Bold = True
    WorkSheet2.Options.TitlesFormat.Font.Name = "Arial"
    WorkSheet2.SheetName = "country"
    WorkSheet2.SQLCommand = oleDbCommand2
    WorkSheet2.StartDataCol = CType(0, Byte)
    cellExport1.Sheets.Add(WorkSheet1)
    cellExport1.Sheets.Add(WorkSheet2)
    cellExport1.SQLCommand = oleDbCommand1

    oleDbConnection1.Open()
    Try
        cellExport1.SaveToFile()
    Finally
        oleDbConnection1.Close()
    End Try
End Sub

Private Sub cellExport1_GetDataParams(ByVal sender As Object, ByVal e As Spire.DataExport.EventArgs.DataParamsEventArgs) Handles cellExport1.GetDataParams
    If (e.Sheet = 0) AndAlso (e.Col = 6) Then
        e.FormatText = cellExport1.DataFormats.Currency
    End If
End Sub

This sample demonstrates how to export data table to HTML.

private void button1_Click(object sender, EventArgs e)
{
    System.Data.OleDb.OleDbConnection oleDbConnection1
         = new System.Data.OleDb.OleDbConnection();
    oleDbConnection1.ConnectionString
        = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=..\..\..\..\Database\demo.mdb";

    System.Data.OleDb.OleDbCommand oleDbCommand1
        = new System.Data.OleDb.OleDbCommand();
    oleDbCommand1.CommandText = "select * from parts";
    oleDbCommand1.Connection = oleDbConnection1;

    Spire.DataExport.HTML.HTMLExport htmlExport1
         = new Spire.DataExport.HTML.HTMLExport();

    htmlExport1.ActionAfterExport = Spire.DataExport.Common.ActionType.OpenView;
    htmlExport1.DataFormats.CultureName = "zh-CN";
    htmlExport1.DataFormats.Currency = "c";
    htmlExport1.DataFormats.DateTime = "yyyy-M-d H:mm";
    htmlExport1.DataFormats.Float = "g";
    htmlExport1.DataFormats.Integer = "g";
    htmlExport1.DataFormats.Time = "H:mm";
    htmlExport1.FileName = "test.html";
    htmlExport1.HtmlTableOptions.BackColor = System.Drawing.Color.FromArgb(((System.Byte)(0)), ((System.Byte)(122)), ((System.Byte)(236)));
    htmlExport1.HtmlTableOptions.FontColor = System.Drawing.Color.FromArgb(((System.Byte)(255)), ((System.Byte)(255)), ((System.Byte)(255)));
    htmlExport1.HtmlTableOptions.HeadersBackColor = System.Drawing.Color.FromArgb(((System.Byte)(255)), ((System.Byte)(0)), ((System.Byte)(0)));
    htmlExport1.HtmlTableOptions.HeadersFontColor = System.Drawing.Color.FromArgb(((System.Byte)(255)), ((System.Byte)(255)), ((System.Byte)(255)));
    htmlExport1.HtmlTableOptions.OddBackColor = System.Drawing.Color.FromArgb(((System.Byte)(0)), ((System.Byte)(107)), ((System.Byte)(206)));
    htmlExport1.HtmlTextOptions.BackgroundColor = System.Drawing.Color.FromArgb(((System.Byte)(51)), ((System.Byte)(51)), ((System.Byte)(153)));
    htmlExport1.HtmlTextOptions.Font = new System.Drawing.Font("Arial", 8F);
    htmlExport1.HtmlTextOptions.FontColor = System.Drawing.Color.FromArgb(((System.Byte)(255)), ((System.Byte)(255)), ((System.Byte)(255)));
    htmlExport1.HtmlTextOptions.LinkActiveColor = System.Drawing.Color.FromArgb(((System.Byte)(0)), ((System.Byte)(255)), ((System.Byte)(0)));
    htmlExport1.HtmlTextOptions.LinkColor = System.Drawing.Color.FromArgb(((System.Byte)(105)), ((System.Byte)(239)), ((System.Byte)(125)));
    htmlExport1.HtmlTextOptions.LinkVisitedColor = System.Drawing.Color.FromArgb(((System.Byte)(255)), ((System.Byte)(0)), ((System.Byte)(255)));
    htmlExport1.SQLCommand = oleDbCommand1;

    oleDbConnection1.Open();
    try
    {
        htmlExport1.HtmlStyle = Spire.DataExport.HTML.HtmlStyle.Plain;
        htmlExport1.SaveToFile();
    }
    finally
    {
        oleDbConnection1.Close();
    }
}

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Dim oleDbConnection1 As New System.Data.OleDb.OleDbConnection()
    oleDbConnection1.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=..\..\..\..\Database\demo.mdb"

    Dim oleDbCommand1 As New System.Data.OleDb.OleDbCommand()
    oleDbCommand1.CommandText = "select * from parts"
    oleDbCommand1.Connection = oleDbConnection1

    Dim htmlExport1 As New Spire.DataExport.HTML.HTMLExport()

    htmlExport1.ActionAfterExport = Spire.DataExport.Common.ActionType.OpenView
    htmlExport1.DataFormats.CultureName = "zh-CN"
    htmlExport1.DataFormats.Currency = "c"
    htmlExport1.DataFormats.DateTime = "yyyy-M-d H:mm"
    htmlExport1.DataFormats.Float = "g"
    htmlExport1.DataFormats.[Integer] = "g"
    htmlExport1.DataFormats.Time = "H:mm"
    htmlExport1.FileName = "test.html"
    htmlExport1.HtmlTableOptions.BackColor = System.Drawing.Color.FromArgb(CByte(0), CByte(122), CByte(236))
    htmlExport1.HtmlTableOptions.FontColor = System.Drawing.Color.FromArgb(CByte(255), CByte(255), CByte(255))
    htmlExport1.HtmlTableOptions.HeadersBackColor = System.Drawing.Color.FromArgb(CByte(255), CByte(0), CByte(0))
    htmlExport1.HtmlTableOptions.HeadersFontColor = System.Drawing.Color.FromArgb(CByte(255), CByte(255), CByte(255))
    htmlExport1.HtmlTableOptions.OddBackColor = System.Drawing.Color.FromArgb(CByte(0), CByte(107), CByte(206))
    htmlExport1.HtmlTextOptions.BackgroundColor = System.Drawing.Color.FromArgb(CByte(51), CByte(51), CByte(153))
    htmlExport1.HtmlTextOptions.Font = New System.Drawing.Font("Arial", 8.0F)
    htmlExport1.HtmlTextOptions.FontColor = System.Drawing.Color.FromArgb(CByte(255), CByte(255), CByte(255))
    htmlExport1.HtmlTextOptions.LinkActiveColor = System.Drawing.Color.FromArgb(CByte(0), CByte(255), CByte(0))
    htmlExport1.HtmlTextOptions.LinkColor = System.Drawing.Color.FromArgb(CByte(105), CByte(239), CByte(125))
    htmlExport1.HtmlTextOptions.LinkVisitedColor = System.Drawing.Color.FromArgb(CByte(255), CByte(0), CByte(255))
    htmlExport1.SQLCommand = oleDbCommand1

    oleDbConnection1.Open()
    Try
        htmlExport1.HtmlStyle = Spire.DataExport.HTML.HtmlStyle.Plain
        htmlExport1.SaveToFile()
    Finally
        oleDbConnection1.Close()
    End Try
End Sub