Changer de plage.....de cellules

Private Sub Workbook_Open()
Dim Cell As Range, Msg As String
With Feuil1
    For Each Cell In .Range("A4:A256")
        If Cell = "" Then
            result = MsgBox("Première Cellule Vide de la plage " & .Range("A4:A256").Address(0, 0) _
            & vbCrLf & "==> " & Cell.Address, vbOKCancel, "Rester sur la plage ?")
            If result <> vbCancel Then
                Cell.Activate
                    Exit Sub
            End If
            Exit For
        End If
    Next Cell
    'sinon
    For Each Cell In .Range("A268:A380")
        If Cell = "" Then
            MsgBox "Première Cellule Vide " & Cell.Address
            Cell.Activate
            Exit For
        End If
    Next Cell
End With
End Sub