Having trouble with the PCRE syntax

[strike]

Hi,

would anybody please tell me what I'm doing wrong here?

location ~* ^/(forum|forums|board)/? {
     rewrite ^/([^/]*)/*(.*) http://forum.my_domain.com/$2
permanent;
}

I'd like to make it redirect visitors from
http://www.my_domain.com/forum (note: there's no trailing slash),
http://www.my_domain.com/forum/, http://www.my_domain.com/forums (again,
there's no trailing slash here), http://www.my_domain.com/forums/,
http://www.my_domain.com/board (...yep) and
http://www.my_domain.com/board/ to http://forum.my_domain.com/. Neither
the path (except "forum"/"forums"/"board") nor the query (if there's
one) should get cut off. It's working so far, but it also redirects
visitors from ex. http://www.my_domain.com/forumfoobar/, which isn't
what I want. :-(

Thanks in advance!

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,182278,182278#msg-182278