With this VBscript, xls donation excel is saved as xlsx.
Sub SaveAs()
Dim objExcel
Dim objWorkBook
fileName="C:\RobustaWorkspace\out\result.xls"
newFileName="C:\RobustaWorkspace\out\LastResult.xlsx"
'Instantiate Excel
Set objExcel = CreateObject("Excel.Application")
'open the xls file
Set objWorkBook=objExcel.Workbooks.Open(fileName)
'Save the file as excel workbook
objWorkBook.SaveAs(newFileName),
'close workbook
objWorkBook.Close 'False
'quit excel
'objExcel.Quit
'clean up
'Set obj WorkBook = Nothing
'Set objExcel = Nothing
End Sub