can somebody help me to rewrite this?

[escavern]

Hi guys, i really need some help here. I plan to move my forum from the root
domain to a subfolder named "/forum"

I need to rewrite from:
www.mywebsite.com/showthread.php?t=123456

To

www.mywebsite.com/forum/showthread.php?t=123456

I hope you guys can help me to find out the rewrite rules.
Thank you!

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,259077,259077#msg-259077