Dynamic URL redirect

Hello there;
in my website, I use the root directory for my main script "vBulletin"
now I want to move my vBulletin script into a child-directory "forums" and use the main dir for another script.
I use vBseo for URL re-writing and the option I use for re-writing is

t[thread_id]/[thread_title].html

Code (markup):

example

http://www.example.com/t20836/thread-title.html

Code (markup):

RECOMMENDED

I want to move it to

http://forums.example.com/t20836/thread-title.html

Code (markup):

or


please not, that I can't use this mod_rewrite

Options +FollowSymLinks
RewriteEngine on
RewriteRule (.*) http://forums.example.com/forums/$1 [R=301,L] 

Code (markup):

because if I did I won't be able to use the main directory of my domain

I think if we could find a way to get the [thread_id] from the folder name and redirect the visitor to
/forums/showthread.php?t=[thread_id]
I think then the problem will be solved.
Any ideas?
hope someone can help.

 

Problem solved using

RewriteEngine On 
Options +Indexes
Options +FollowSymlinks
RewriteRule ^t(.*)/(.*)\.html$ http://www.example.com/forums/showthread.php?t=$1 [R=301]

Code (markup):

I've found that solution after 5 hours googling and reading different articles, and actually this one was the most helpful.

http://forums.digitalpoint.com/showthread.php?t=23044

Code (markup):

 

That is the best solution to this kind of redirect problems. With it you match only the files you want. It should work fine.