Macros
In the Visual Basic Editor, programmers can protect macros so that they can't be viewed or changed by users. Programmers can protect macros by using the Protection tab of the Project Properties dialog box in the Visual Basic Editor (Tools menu, Project Properties command). For more information, see Visual Basic Editor Help.
Assuming you have access to Excel 2000, use the visual basic editor help to look up the following topics;
-Protect workbooks and worksheets from changes
-About protecting workbooks and worksheets from changes