[exim] Smart routing problem

Helo Fellow Exim Users

I have a mailserver that handles mail for only one domain.

But not all of the users of the domain is on the local server.

I want to create a router that tells the server to query a file. If it
matches a recipient for the local domain in that file, it needs to use
the remote_smtp transporter for it.

This is what I have in my exim configuration:
unknown:
 driver = manualroute
 transport = remote_smtp
 route_data =     lsearch;/usr/local/etc/exim/alias.remote   
 no_verify

No looking at some examples, I think that that is the right way of
setting up the router, but I am not sure what my lsearch'd file should
look like inside?

I tried stuff like:
user.domain.co.za: remote_server.co.za
user: remote_server.co.za

But none work :(

I get the following error:
opened hints database /var/spool/exim/db/retry: flags=2
address match: subject=*@domain.co.za pattern=*
domain.co.za in "*"? yes (matched "*")
*@domain.co.za in "*"? yes (matched "*")
retry for R:domain.co.za = *

Now the "match" word tells me it does indeed find a match in the file,
but the problem lies here:
2004-11-06 12:19:57 1CQNfp-0000Rg-1d no IP address found for host
lsearch;/usr/local/etc/exim/alias.remote

Does the no IP address found mean I have a config problem in my lsearch
file?

can someone please point me in the right direction?

Thanks

Wayne