Date stamp in absolute column

[reoryn]

Ok, I've got a sheet with lots of columns. Each time someone makes a change in any row of any one of those columns, I want it to date stamp it in an extra column on the end so we always know who made the last change to each row and when. The actual entering of the data isn't a problem, the problem I'm having is getting it to always put the data stamp in the right column or row.

The code I've got is :-

If Target.Cells.Count > 1 Then Exit Sub
        If Not Intersect(Target, Range("A2:D100")) Is Nothing Then
            With Target(1, (10 - ActiveCell.Column))
                .Value = Date
                .EntireColumn.AutoFit
            End With
        End If

Which is great if the user presses Enter after typing, but if they press the left or right arrows, the datestamp appears one cell to the left or right of where it's supposed to be. I'm sure it's simple to make it an absolute column but it's doing my head in.

Thanks!