You need to add a COM reference in your project to the "Microsoft Excel 11.0 Object Library" - or whatever version is appropriate.
This code works for me:
private void AddWorksheetToExcelWorkbook(string fullFilename,string worksheetName)
{
Microsoft.Office.Interop.Excel.Application xlApp = null;
Workbook xlWorkbook = null;
Sheets xlSheets = null;
Worksheet xlNewSheet = null;
try {
xlApp = new Microsoft.Office.Interop.Excel.Application();
if (xlApp == null)
return;
// Uncomment the line below if you want to see what's happening in Excel
// xlApp.Visible = true;
xlWorkbook = xlApp.Workbooks.Open(fullFilename, 0, false, 5, "", "",
false, XlPlatform.xlWindows, "",
true, false, 0, true, false, false);
xlSheets = xlWorkbook.Sheets as Sheets;
// The first argument below inserts the new worksheet as the first one
xlNewSheet = (Worksheet)xlSheets.Add(xlSheets[1], Type.Missing, Type.Missing, Type.Missing);
xlNewSheet.Name = worksheetName;
xlWorkbook.Save();
xlWorkbook.Close(Type.Missing,Type.Missing,Type.Missing);
xlApp.Quit();
}
finally {
Marshal.ReleaseComObject(xlNewSheet);
Marshal.ReleaseComObject(xlSheets);
Marshal.ReleaseComObject(xlWorkbook);
Marshal.ReleaseComObject(xlApp);
xlApp = null;
}
}
Note that you want to be very careful about properly cleaning up and releasing your COM object references. Included in that StackOverflow question is a useful rule of thumb: "Never use 2 dots with COM objects". In your code; you're going to have real trouble with that. My demo code above does NOT properly clean up the Excel app, but it's a start!
Some other links that I found useful when looking into this question:
According to MSDN
To use COM interop, you must have administrator or Power User security permissions.
Hope that helps.