[exim] database-driven forwarding

What I want to do is provide email forwarding to user ID's found in a database table. Currently, emails are forwarded based on the contents of the text file /etc/valiases/{$domain}. I can run a script that will build this file using the information in the database, and this script can be set up as a cron job. Practically, this solution would, I think, work just fine for what I need.

On the other hand, I would like to be able to configure Exim to forward emails based on the actual content of the database, not on the static file in the valiases directory. I use Exim under cPanel, so it's not configured for MySQL lookups; however, I had thought that I could still get a data from a MySQL database simply by using a perl subroutine. Is this possible? I've been experimenting with approaches as basic as simply trying to get Exim to use data from a forwarding file other than /etc/valiases/{$domain}, and the results have not been encouraging.

Thanks,

Rick