Dim App As New MSExcel.Application
Dim Wb As MSExcel.Workbook = App.WorkBooks.open("d:\test.xls")
Dim Ws As MSExcel.WorkSheet = Wb.WorkSheets(1)
Dim Rg As MSExcel.Range = Ws.UsedRange
rg.Copy
rg.PasteSpecial(Paste:=MSExcel.XlPasteType.xlPasteValues, Operation:=MSExcel.XlPasteSpecialOperation.xlPasteSpecialOperationNone, SkipBlanks:=False, Transpose:=False)
Wb.Save
App.Quit