Question about IIS, DNS, and ISA

Archived from groups: microsoft.public.win2000.advanced_server (More info?)

I will try not to make this complicated.

I have my my server setup the following way:

titan.local as my first DNS entery.
company1.com 2nd entery
company2.com 3rd entery

etc.

Since I only have 1 static IP from the internet I have setup host files on
all the IIS enteries for the websites. All this sits behind my ISA server.

My question now is, if there is anyway to assign internal IPs to each of the
web sites, and have ISA just forware the HTTP request to the correct the
site? Second how to I get DNS to properly load up each page from the
internal side of the network after each one gets their own IP address?

I am looking at getting MAPI working for each client, which requires SSL and
a IP for each site.

Thanks
Andrew