Does any one know how to map foreign key fields to cmp fields to make this kind of relation ship in JBoss to work?

User
user_pk
name

UserRole
user_pk
role_pk
status

Role
role_pk
name

I know from other topics that I need to create an entity UserRole with a compound primary key (user_pk, role_pk). But may I configure jbosscmp-jdbc to use this compound pk as a relation cmr? Any examples?

Thanks in advance.
eugenio.