Prior to getting EXCEL 2003, this is the macro I used to have to run (from
another workbook) to remove all traces of a macro:

Sub RemoveMacros()
Dim O As Object
For Each O In ActiveWorkbook.Sheets
If TypeName(O) = "Worksheet" Then
Select Case O.Type
Case xlExcel4MacroSheet, xlExcel4IntlMacroSheet
Application.DisplayAlerts = False
O.Delete
Application.DisplayAlerts = True
End Select
End If
Next
With ActiveWorkbook.VBProject
For Each O In .VBComponents
Select Case O.Type
Case 1, 2 ' standard or class module
.VBComponents.Remove O
Case Else ' form or document
With O.CodeModule
.DeleteLines 1, .CountOfLines
End With
End Select
Next
End With
End Sub

I've never needed to use it for EXCEL 2003, so I'm not sure if it would
still work for it or not...