Bonjour,
Une méthode
Sub test()
Dim Dico, k, a
Dim i As Long
Dim Liste As String
Set Dico = CreateObject("scripting.dictionary")
a = Feuil1.UsedRange
For i = 2 To UBound(a)
Dico.Item(a(i, 1)) = ""
Next i
For Each k In Dico.Keys
Liste = Liste & k & ","
Next k
With Feuil1.[L1].Validation
.Delete
.Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, Operator:= _
xlBetween, Formula1:=Left(Liste, Len(Liste) - 1)
End With
End Sub
A+