این کدو پیدا کردم ، جواب داد ..
پ ن : من ده تا شیت دارم که شیت Worksheets[8] تو خط 13 برام شیت دومو چاب می کنه
void PrintMyExcelFile()
{
Excel.Application excelApp = new Excel.Application();
// Open the Workbook:
Excel.Workbook wb = excelApp.Workbooks.Open(@"C:\My Documents\Book1.xls",
Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing, Type.Missing, Type.Missing);
// Get the first worksheet.
// (Excel uses base 1 indexing, not base 0.)
Excel.Worksheet ws = (Excel.Worksheet)wb.Worksheets[8]; // sheet dovom
// Print out 1 copy to the default printer:
ws.PrintOut(
Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing, Type.Missing, Type.Missing);
// Cleanup:
GC.Collect();
GC.WaitForPendingFinalizers();
Marshal.FinalReleaseComObject(ws);
wb.Close(false, Type.Missing, Type.Missing);
Marshal.FinalReleaseComObject(wb);
excelApp.Quit();
Marshal.FinalReleaseComObject(excelApp);
}