Help with Excel Username Generator..

Hey.. I am trying to use the following excel formula to create a username generator.... i found it in a google apps discussion.. but noone mentioned how to use it to actually generate usernames.... here is the excel formula....gotta login with your google account to view it.......http://spreadsheets.google.com/ccc?key=pEOsh2Vs5KPKah_48J7kRUw...