sulla rete ho trovato questo codice che sembra fare al mio caso...
Private mComm As String
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Application.EnableEvents = False
If Not Intersect(Target, Range("K7:L9")) Is Nothing Then
mComm = Target.Comment.Text
End If
If mComm <> "" Then
If Not Intersect(Target, Range("A3:B8")) Is Nothing Then
Target.ClearComments
Target.AddComment mComm
mComm = ""
End If
End If
Application.EnableEvents = True
End Sub