How can I setup a forum and archive all threads & posts from certain date?

Well, you could make a new forum and not allow any post permissions (write) to any users; this would ensure no one posting in the archive forum; then simply use the mass move tool (Content Management -> Move Topics) and simply select your source and target forums and date ranges to select; it should be ultimtely painless.

Thank you. Painless always works for me! You response is very much appreciated.

Lol not a problem :).

As things go forward with the UBB and we eventually get to MySQL 5 as a minimum requirement (which will be a few years away, heck myself Im only running MySQL 4) I can't wait to see if we'd be able to get the archive table type (MySQL5+) for true archive forums...

(I hope my friend Russell will take the time to post a little bit on here about the archive table type, he does the web-presance work at the US Census so they put him through a lot of classes, lucky bum)...