Need help with making a database

I have 70 sports teams with all different rosters I need to input, but I need to input 11 rosters where if any of those names show up in the 59 other teams I need to know. Basically those 11 teams have players that are too good for the other levels and they aren't allowed to play in both. Without having to search a name one by one, how can I enter this info and have the program "alert me" or highlight the names that are on multiple teams? I have MS Office, Excel, and Word. Or does anyone know of anything else free?