Hi Brian,
Assuming that you have data in column A and that the first cell is A1, the
following macro should do the job. It will do nothing if there are four or
fewer characters in a cell.

Option Explicit
Dim CountRows As Double
Dim Iloop As Double
Sub DeleteCharacters()

'Turn off warnings, etc.
Application.ScreenUpdating = False
Application.DisplayAlerts = False

CountRows = Cells(Rows.Count, "A").End(xlUp).Row
For Iloop = 1 To CountRows
   If Len(Cells(Iloop, "A")) > 4 Then
       Cells(Iloop, "A") = Right(Cells(Iloop, "A"), _
       Len(Cells(Iloop, "A")) - 4)
   End If
Next Iloop
   
'Turn off warnings, etc.
Application.ScreenUpdating = True
Application.DisplayAlerts = True
End Sub

Sub trimleftfour()
lr = Cells(Rows.Count, "f").End(xlUp).Row
For Each c In Range("f2:f" & lr)
c.Value = Right(c, Len(c) - 4)
Next c
End Sub

What are you doing wrong.........?

You cannot record or run a macro while in Edit mode which is the mode you are in
when deleting the first four characters.

See the macros from Don and Ken to get what you want.

Gord Dibben  MS Excel MVP