1) Add a reference in your Visual Studio project to docuPrinter library. To do this: On the Project menu, click Add Reference; On the COM tab, locate docuPrinter Library and then click Select; Click OK in the Add References dialog box to accept your selections. 2) Add a reference in your project to Microsoft Excel. To do this: On the Project menu, click Add Reference. On the COM tab, locate Microsoft Excel and then click Select. Click OK in the Add References dialog box to accept your selections.

private void button1_Click(object sender, EventArgs e)
{

    string fileToConvert = @"c:\test.xls";
    docuPrinter.SDK DPSDK = new docuPrinter.SDK();

    DPSDK.DocumentOutputFormat = "PDF";
    DPSDK.DocumentOutputName = "demoXLS";
    DPSDK.DocumentOutputFolder = @"c:\ ";

    DPSDK.PDFAutoRotatePage = "All";

    DPSDK.HideSaveAsWindow = true;
    DPSDK.DefaultAction = 1;
    DPSDK.ApplySettings();

    // If you have Excel 2000 or XP remove the next 2 lines
    Microsoft.Office.Interop.Excel.Application MSExcel =
    new Microsoft.Office.Interop.Excel.Application();
    Microsoft.Office.Interop.Excel._Workbook XLBook;

    // If you have Excel 2000 or XP uncomment the lines below
    // Excel.Application MSExcel = new Excel.Application();
    // Excel._Workbook XLBook;


    MSExcel.DisplayAlerts = false;

    try
    {
      // This line will work only with MS Excel XP / 2003
      XLBook = MSExcel.Workbooks.Open(fileToConvert, 0, true, 5, "", "",
      true, 2, "", false, false, false, false, 1, false);

      // for MS Excel 2000 use the line below
      // XLBook = MSExcel.Workbooks.Open(fileToConvert, 0, true, 5, "", "",
      //  true, 2, "", false, false, false, false);

    } catch {
      MSExcel.Quit();
      return;
    }

    XLBook.Activate();
    XLBook.PrintOut(1, 9999, 1, false, "docuPrinter", true, 0, "");

    XLBook.Saved = true;
    XLBook.Close(false, "", false);
    MSExcel.Quit();
    MSExcel = null;

    int RVal = DPSDK.Create(300); // Create output document            
    DPSDK = null;

    if (RVal != 0) {
       MessageBox.Show("Error while creating document!!!");
    } else {
       MessageBox.Show("Done converting!!!");
    }

}