Yes Newmie, I get it now.
Try the following code:
Private Sub Worksheet_Change(ByVal Target As Range)
Dim x As Integer
If Intersect(Target, Columns("B:B")) Is Nothing Then Exit Sub
x = Target.Offset(0, -1).Value
Target.Offset(0, -1) = x
Right-click the sheets tab and select "View code". Paste the code in the big white field.
Monday, Tuesday and Thursday are usually the days I'll respond. Bear this in mind when awaiting a reply.