Calcul de la somme de plusieurs colonnes

Option Explicit
'----------------------------------
Sub totaliser_colonnes()
Dim Derlig As Integer, DerCol As Integer, Lig As Integer, Col As Integer

    Application.ScreenUpdating = False
    
    With ActiveSheet
        Derlig = .Columns("E").Find(what:="*", searchdirection:=xlPrevious).Row
        DerCol = .Rows(5).Find(what:="*", searchdirection:=xlPrevious).Column
        Lig = Derlig + 1
        For Col = 5 To DerCol
            .Cells(Derlig, Col) = Application.Sum(.Range(.Cells(5, Col), .Cells(Derlig, Col)))
        Next
    End With
End Sub