i have a question about EJB CMR with many-to-many relation.

i have 2 tables:
1. students.
2. courses.

every student has a:
- name (primary key)
- sexuality

every course:
- name (primary key)
- type

for examle, sorry i hasn'T another, i want to map students-to-courses
over the fields:
student.sexuality to course.type

both fields aren't primary keys.
my questions are:
can i do it with CMR?
and how ??

thank you,