How do I carry forums across domains?

[syrus.xl]

Originally Posted by harleyparts

you simply forword the domain to the address you want it to be pointed too.

its done from your server or host not thru , its very easy

Perhaps, I didn't explain myself correctly.. Here's the brief idea. If I point the other domain to the other, that will just duplicate all content and that is not what we require.

Domain1.com/forum
Forum Category 1 <-- Forum Specific to this domain
-- Introductions
-- General
-- Lounge
Forum Category 2 <-- Duplicated Category across domains
-- X - Graphix
-- X - Designs
-- X - Source Files
-- X - Resources

However, domain2.com would show only Forum Category 2 on both domains, but not Forum Category 1 from Domain1.com. Basically, 2 different forums apart from one category of forums.

Domain2.com/forum
Forum Category 1 <-- Forum Specific to this domain
-- Members
-- Design Formats
-- RGB Settings
-- Profiling Settings
Forum Category 2 <-- Duplicated Category across domains
-- X - Graphix
-- X - Designs
-- X - Source Files
-- X - Resources

Regards,