Hi,
Here's a bit of code that will fire if cell A16 is changed.
Code:
Private Sub Worksheet_Change(ByVal Target As Range)
'Do nothing if more than one cell is changed or content deleted
If Target.Cells.Count > 1 Or IsEmpty(Target) Then Exit Sub
If Target.Address = "$A$16" Then
Application.EnableEvents = False
''''''''''''''''Your code ''''''
Application.EnableEvents = True
End If
End Sub