[exim] openldap + exim, how to make mailing group ?

helo.

I use openldap + samba, and i want to use exim with it.
i want to use posixGroup to make group mail.

If i use this router, i get only memberUid.

postgroup:
    driver      = redirect
    allow_fail
    allow_defer
    data = ${lookup ldapm{LDAP_AUTH \

ldap:///ou=People,dc=xxx,dc=org?memberUid?sub?(cn=${quote_ldap:$local_part})}}


How i can get mail attribute from memberUid?



Thanks.

--
Bet regards, George.