Hi

Private Sub Worksheet_Change(ByVal Target As Range)
   If Target.Column = 12 And Target.Row = 16 Then
       ' Add your code here
       MsgBox "There was a change in cell L16"
   End If
End Sub

Arvi Laanemets

Worksheet_Change monitors all cells, you just need to tell it which one,
like this

Private Sub Worksheet_Change(ByVal Target As Range)
If Not Application.Intersect(Target, Range("L16")) Is Nothing Then
   OtherMacro
End If
End Sub

This will run a macro called OtherMacro if cell L16 is changed.

Now you need to beware if the macro makes other changes to the worksheet or
else you code will be called each time it is.  You can prevent this by
adding

Application.EnableEvents=False

but remember to turn them back on at any place where code can exit
(including errors) or you will be left with no events at all in Excel