Sub som()
Dim n As Variant
Dim Tot As Double
Dim cel As Range
For n = 4 To 4 + 32
Tot = 0
prenom = Sheets('Planning').Cells(3, n)
Worksheets('feuil1').Activate
For Each cel In Worksheets('Feuil1').Range(Cells(1, 56), Cells(10, 79))
If cel = prenom Then Tot = Tot + cel.Offset(0, -1)
Next cel
Sheets('Planning').Cells(5, n) = Tot
Next n
End Sub