Extend Ria services profile provier to custom table using ASP.Net memberships

I am sort of new to Silverlight  but definitely  new to Ria services. I understand it uses the ASP.Net membership tables so I was hoping to extend it a little. I am interested in extending the user profile to a new table. I came across this ASP.net tutorial. It describes nicely how to have your own table to store profile info and how to add a row to it (using UserId) when the new user is created upon registration.
http://www.asp.net/web-forms/tutorials/security/membership/storing-additional-user-information-cs
It explains exactly my needs. It shows by means of an event handler how to add a row into your custom profile table just after the Create user event is completed. I was hoping this solution could be ported into the Default "Silverlight business application template". However I am stumped as to where to fit ...