Sub Test()
Dim o, i, MesCodes, TableCodes
Set TableCodes = CreateObject("scripting.dictionary")
MesCodes = Feuil1.[A2:A11]
For i = 1 To UBound(MesCodes): TableCodes.Add MesCodes(i, 1), i: Next
For Each o In Feuil2.[B2:B19]
If Not TableCodes.Exists(o.Value) Then o.Value = "Autre"
Next
Set TableCodes = Nothing
End Sub