This is the only way i have found, but how to change it to work with a
range, not just one cell.

Public A


Private Sub Worksheet_Change(ByVal Target As Excel.Range)
Application.EnableEvents = False
[a1] = [a1] + A
Application.EnableEvents = True
End Sub


Private Sub Worksheet_SelectionChange(ByVal Target As Excel.Range)
A = [a1]
End Sub