[Exim] host_accept_relay nag

Greetings All...

I have an wierd issue with version 3.03 and the host_accept_relay stuff.
If goes like this:

I would like to add a list of IP addresses to host_accept_relay that are
allowed to relay through me. If I add the address to the tag within my
exim config file, everything is happy.

BUT

I _must_ add the entries to an outside file. I put the required
lsearch;/my/file/name entry into the exim config file and it refuses to
relay. When I try exim -d9 -bh, I see that it's searching on the host
name that it resolves, not the IP address. Any way I can change this
behaviour.

I have tried mucking with the host_lookup tag, and I do use the
host_deny option.

Any other ideas???

Chris Read