Virtual Domains

I use Fedora Core 3 and Exim 4.43. The way I have things configured
every sent to my one domain comes to my user except for 2 other local
users.

Recently I added another domain and pointed it to my Fedora Core 3
system. I use Apache and virtual hosts to run the two web sites from
that one machine.

But not I'd like to tell exim that <anything>@domain2.com ->
<myuser>@domain1.com.

How do I configure that?

BTW emailed responses are preferred as 1) I don't read this newsgroup
often and 2) my ISP decided that business customers (well customers
with a static IP) don't need Usenet newsgroups and 3) I don't like
reading things through Google groups.

Thanks...