Capitalize Last Names in Access Database Field

Hello,

I know this is an excel forum, but I also know many of you are proficient in all things Microsoft Office and was wondering if someone could help with automatically capitalizing all Last Names in an Access Database.

I cannot create another column or field with this information, because I do not know how that would affect the program that is accessing this database. Ideally, I could run a macro, that would captialize all the last names and then closes out of the database.