エクセルオープン
既存のエクセルをよみこみ
xls.Workbooks.Open(FileName, System.Type.Missing, System.Type.Missing, System.Type.Missing, System.Type.Missing, System.Type.Missing, System.Type.Missing, System.Type.Missing, System.Type.Missing, System.Type.Missing, System.Type.Missing, System.Type.Missing, System.Type.Missing, System.Type.Missing, System.Type.Missing);
なかなか読めなくて苦労する