[Exim] autogenerated aliases

hi,
is it possible to build aliases automatically via mysql?

let's say i want an alias to be all@???, all my users are in
mysql, so the lookup would be "select local_part, domain from users,
domains where users.did = domains.did", but how would you set this up in
the exim configuration file?

-- 
        - randall s. ehren -=- 805 893-5632
           system administrator -=- isber.ucsb.edu
            institute for social, behavioral, and economic research
             805 341-5947 cell  or randall.cell@???