[exim] route mail to remote host

Hello,

I want to reroute emails from either a specific external source IP or
$local_part to a remote host on an alternate port. I was originally
looking at using manualroute as you are able to specify a transport with
the different port number, but from what I can see I am only able to use
the domain part of the address and not the source IP or local_part - is my
understanding correct ?

I am probably missing something but from what I have read so far it is not
100% clear.

Any pointers or ideas would be great.

Jason