Décaler les cellules vers le haut, fichier excel VB.NET

        Dim xlsapp As Microsoft.Office.Interop.Excel.Application
        Dim Xlsbook As Microsoft.Office.Interop.Excel.Workbook
        Dim xlWorkSheet As Microsoft.Office.Interop.Excel.Worksheet
        Dim misValue As Object = System.Reflection.Missing.Value

        xlsapp = New Microsoft.Office.Interop.Excel.Application
        Xlsbook = xlsapp.Workbooks.Open("\\vmware-host\Shared Folders\Bureau\KOTTMANNBDOX.xls")
        xlWorkSheet = Xlsbook.Sheets(1)
        Dim DEL = xlWorkSheet.Rows.Count - 1
       

 For i = 1 To DEL
         If xlWorkSheet.Cells(DEL, 1).Value = Nothing Then
                xlWorkSheet.Rows(DEL, 1).Delete(Ascending)
 End If
        Next


        Xlsbook.Save()
        Xlsbook.Close()
        Xlsbook = Nothing
        xlsapp.Quit()
        xlsapp = Nothing
        GC.Collect()
        GC.WaitForPendingFinalizers()
        GC.Collect()
        killExl()
        ReleaseObject(xlsapp)
        ReleaseObject(Xlsbook)
        ReleaseObject(xlWorkSheet)