[Samba] Mapping directories based on group membership

[Scott Gross]

I'm using Samba 3.0.2 and LDAP backend.  I have users assigned to groups
based on their departments.  I also have a directory created for each
department.  What I want to do is map a drive letter to a user's department
directory. The groups are also secondary groups as the primary group for
every user is 'Domain Users'.  Does anyone know a way to accomplish this?
What I'm kind of looking for is a group home directory type situation?