Sub Bouton3_QuandClic()
Dim c As Comment
Dim ws As Worksheet
Set ws = Sheets("feuil1")
For Each c In ActiveSheet.Comments
Select Case c.Parent.Address(0, 0)
Case "B5": c.Text "CA= " & ws.Range("a1") & Chr(10) & "MG= " & ws.Range("a2")
Case Else: c.Text c.Parent.Text
End Select
Next c
End Sub