Sub Validation()
Dim L As Long, I As Long
Dim N As Byte ''Byte' à changer en 'Integer' si le nb de scénario peut dépasser 255
With Sheets('Feuil3')
L = .Range('N65536').End(xlUp).Row
For I = 1 To L
If Not (.Cells(I, 1) Like 'scenario_*') Then
.Cells(I, 1).Value = 'scenario_' & N + 1 & '\'
Else
N = Val(Mid(.Cells(I, 1), 10))
End If
Next I
End With
End Sub