When you write a macro in any Microsoft Office application such as Microsoft Word, Microsoft Excel, Microsoft Power Point and Microsoft Access and any Visual Basic for application code, this add in will do the following: Format the code correctly. Add line numbers. Add error handler. Why its useful. The VBA code is not auto formatting, so it is nice to format it. The line numbers in VBA are a good reference for debugging your code. Error handler will prevent your code form crashing.