public static void addRows() { // Select the Excel cells, in the range c1 to c7 in the worksheet. Microsoft.Office.Interop.Excel.Range aRange = excelWorksheet.get_Range("C1", "C7"); if (aRange == null) { Console.WriteLine("Could not get a range. Check to be sure you have the correct versions of the office DLLs."); } // Fill the cells in the C1 to C7 range of the worksheet with the number 6. Object[] args = new Object[1]; args[0] = 6; aRange.GetType().InvokeMember("Value", BindingFlags.SetProperty, null, aRange, args); // Change the cells in the C1 to C7 range of the worksheet to the number 8. aRange.Value2 = 21; }