[Exim] Setting up an alias file for multiple domains

Hi

I'm sure this has been asked before, probably under a different
title.. but I wasn't able to find it in the mailing list archive, nor a
direct answer in the documentation, so I hope someone can help me :-)

I've got 2 different domains on my system, say domain1.com and domain2.com
(being lazy - don't want to type out the full thing over and over..)

I want to be able to have a list of e-mail alias', so that
user@??? 's e-mail will be forwarded to user@???, much
like /etc/aliases, but allowing remote address'.

I'd also like to have 2 separate files - 1 for each domain. The idea is
that I'd be able to write a PHP or Perl script to modify this file to add
or remove entries.

I've looked into using a mysql database, but I'm using Debian Linux, and
the Debian distribution of Exim doesn't come with mysql support - and all
attempts at building a version which does have failed.

Any help would be greatly appreciated :-)

Thanks,

Tim