Is it possible

In Squid 2.2ST3 to do the following.

Depending of the domain the user connects from, Squid should choose
between two Parent's to get the page from.

Say..

Everyone from test.com who connects to squid, then squid should get the
pages from Parent_1.

Everyone else who connects, then squid should get the pages from
parent_2.

Is this possible? Should I start two Squid's on different ports and
force test.com-domainusers to connect to squid_1 and everone else to
squid_2 (on another port) but both share the same cache?

If you don't understand what I mean, mail me!

Thanks for the help ..

-- 
Martin Svensson
Network Engineer
University Hospital of Malmoe
Email: martin@admin.mas.lu.se