How to specify where RSS is grabbed from?

[shooptek]

Hey all,
I am trying to figure out how I can customize what forums RSS pulls from, instead of all of them.

I know that I access my RSS at:
http://bunkerama.com/vbull/external.php?type=RSS2

But how do I customize which forums it pulls from?

Thanks

[private_ale]

...../external.php?type=RSS2&forumids=X,X,X

where X is the ID of the forum you want the rss to come from