//Create a document
Document doc = new Document();
//Add a section
Section sec = doc.addSection();
//Add a paragraph
Paragraph par = sec.addParagraph();
//Load the image
DocPicture picture = new DocPicture(doc);
picture.loadImage("excel.png");
//Insert the OLE
DocOleObject obj = par.appendOleObject("example.xlsx", picture, OleObjectType.Excel_Worksheet);
//Save to file
String output = "insertOLE.docx";
doc.saveToFile(output, FileFormat.Docx_2013);