Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address = "$A$1" Or Target.Address = "$B$1" Or Target.Address = "$A$1" Then
If Range("A1") <> "" And Range("B1") <> "" And Range("C1") <> "" Then
Call mamacro
End If
End If
End Sub
ci joint un fichier : pour tester, remplis les cases A1, B1, C1...la macro se situe dans l'évenement Change de ta feuille.
Private Sub Worksheet_Change(ByVal Target As Range)
If (Range("A1") <> "" And Range("B1") <> "" And Range("C1") <> "") Then
MsgBox "Là tu mets ton action"
End If
End Sub