Rick... Thank you... thank you. This worked perfectly. The string in that
column is always an A or B followed by numbers 1, 2 , 3 or 4. There's no
other variation. I appreciate your help. You are a macro programming
genius... Nay, a VBA god <G. Again thanks :)

"Rick Rothstein (MVP - VB)" wrote in
message ...
Of course, had I actually posted the code that included the error
trapping, that might have been useful.<g

Private Sub Worksheet_Change(ByVal Target As Excel.Range)
If Target.Column = 3 And Target.Row =6 Then
Application.EnableEvents = False
Target.Value = Format(Target.Value, "&&&&&-&")
Application.EnableEvents = True
End If
End Sub

Remember, the above code is for when there is only one trailing digit...
the more general code that I posted in my previous message was complete
as posted.

Sigh! Yes, as I said, if I **had** posted the code with the error
trapping, that would indeed have been useful...

Private Sub Worksheet_Change(ByVal Target As Excel.Range)
If Target.Column = 3 And Target.Row = 6 Then
On Error GoTo CleanUp
Application.EnableEvents = False
Target.Value = Format(Target.Value, "&&&&&-&")
End If
CleanUp:
Application.EnableEvents = True
End Sub

Rick