One Wan IP, Two subdomain

[tobe76]

Hi

I have searched all the net after instruction that will work.
I have read that with Squid3 you will be able to do a reverse proxy so when you enter www.domain.com you will be direct to internal ip xxx.xxx.xxx.254
and if you enter mail.domain.com you will be directed to xxx.xxx.xxx.253
Don't want to use port 444 to come around the problems.

Looking forward to get some good information/instruction.