You have to use the cmr field of the user that is created. After creation you can have an empty Collection on calling the getCMRfield() method. Then you can use the Collection methods to add related CMP's to that collection.
Suppose you hava an collection of roles(CMP's) in a Collection newRoles.
This is just one way. Read the EJB spec for more.
Thanks for your reply
I'm gona to read the EJB Spec