Macro based applications are generally password protected.But its really not so secure( applied for Office 2003 versions only )
To break the password of an excel macro follow the steps :
1. Take a back up of your file.
2. Get a HEX editor (download it from internet there many of them like Ultra Edit etc.)
3. Open your excel file in HEX editor
4. Look for a string “PDB”
5. Change in to “PDx”
6. save file and open it again ( ignore the error message )
7. Go to Macro Editor (Alt+F11)
8. Right click on macro solution and set any password you want ( in the second tab of the opened window)
9. Save it .
10. Now you can open it with your new password.
Note: Breaking password can lead to legal issue . Above information is just for sharing knowledge