Option Explicit
Private Sub But1_Click()
Call RemplirCbs(Cb1, "A")
End Sub
Private Sub But2_Click()
Call RemplirCbs(Cb2, "B")
End Sub
Sub RemplirCbs(Combo As Object, Colonne As String)
Combo.Clear
With Worksheets("feuil1")
Combo.List = .Range(.Cells(1, Colonne), .Cells(.Cells.Rows.Count, Colonne).End(xlUp)).Value
End With
End Sub