Function ADDITION_FEUILLE(FeuilleDebut As String, FeuilleFin As String, Cel1 As String, Cel2 As String) As Double
Dim Total As Double
Dim I As Integer
Application.Volatile
For I = Worksheets(FeuilleDebut).Index To Worksheets(FeuilleFin).Index
Total = Total + (Worksheets(I).Range(Cel1).Value * Worksheets(I).Range(Cel2).Value)
Next I
ADDITION_FEUILLE = Total
End Function