Sub Transfert_RC()
Dim decal As Byte, mois As Byte
Dim f As Worksheet
Dim taille As Integer
decal = 2
mois = Month(Range("zone").Item(1, 3))
Set f = Sheets(1)
taille = f.Range("A" & f.Rows.Count).End(xlUp).Row - 1
With f.Cells(2, mois + decal).Resize(taille)
.Formula = "=vlookup(A2,zone,4,false)"
.Value = .Value
End With
End Sub