[Exim] mailhubbing

Hallo all

I finally found what I was looking for in the FAQ.
http://www.exim.org/exim-html-4.10/doc/html/FAQ_3.html

All I did was change to a file lookup
 hubbed_hosts:
     driver = manualroute
     transport = remote_smtp
     route_list = lsearch;/etc/eximfiles/domainrouting      <-------

Now what troubles me is what does my file entry have to look like to pass the
mail on to the individual hosts?
eg. mydomain.com    [192.168.1.1]
or
mydomain.com    pop3.actualdomain.com

Was I clear enough?

Mozzi