[Exim] Listening on different ports for different addresses

Simple question. I have a local mail server that handles mail for my
internal network. Because of security implementations on my ISP, I have to
recieve mail on port 4000 over the net. So is there a way I can specify a
port to listen to for each address?
i.e. address 192.168.0.1 listens on 25
everyone else listsns on 4000

Thanks