Urgently need a .htaccess rule

[jscieza]

Hi to everyone,

I have been using tfSEO for my forum for 4 months and all URLs (showthread and forumdisplay) has been rewritten with a 301 redirect so now Google has my index with the following URL structure:

http://www.mydomain.com/f149/example...d-title-23313/

However with tfSEO uninstalled (since yesterday), my URLs structure are the classic ones:

http://www.mydomain.com/showthread.php?t=23313

So I urgently need to know if there is possible to set-up a .htaccess rule to 'revert" this redirection. There are more than 12,000 threads on my forum and I really do not want to get millions of 404 erros.

Please help me if you know how I can solve it. I will be very thanked.

Thank you very much for your help!

Joanthan.