[Exim] LDAP for Distribution lists

Why doesn't this work? I want to return all the results mail attributes
where the memberOfGroup = DN of ${lookup ldapdn
{ldap://ldap.doc.state.vt.us/??sub?(cn=${quote_ldap:$local_part})}

more_aliases:
  driver = aliasfile
  search_type = ldapm
  query = ldap://ldap.doc.state.vt.us/\
    ou=People,o=Vermont Department of Corrections,c=US?mail?sub?\
    (memberOfGroup=${lookup ldapdn
{ldap://ldap.doc.state.vt.us/??sub?(cn=${quote_ldap:$local_part})}})
  file_transport = address_file
  pipe_transport = address_pipe
Joseph Kezar