[Dovecot] virtual users with winbind

hi there,

i'm trying to setup virtual users with winbind, i have everything setup in dovecot other than 'Data source for users, homes and IDs'.

i have 'Password authentication source' set to auth_passdb = pam my pam module is using winbind with the mkhomedir.so

i have 'Mail file location' set to default_mail_env = mbox:/home/%u/mail:INBOX=/var/spool/mail/%u

i have 'Data source for users, homes and IDs' set tp auth_userdb = passwd

at the moment my local users can sign in, but my winbind users can't, i'm looking for a way to make auth_userdb look up a pam module, or something ... i don't know what i'm looking for, can someone help me with virtual users with winbind?