Installing onto an addon domain???

[itsallgood]

Hiya guys!

I've setup a addon domain on my itsall3.com site.

I would like to add a forum for the new domain - which is using the same space and bandwidth as the itsall3 account - but works as a completly differnt site.

If i install phpbb through cpanel - the forum is coming up as www.itsall3.com/forum

But i would like it to appear as www.newdomainname.com/forum

Any ideas.

Many thanks.