.htaccess 301 redirection problem

I am having trouble writing a rule for following problem in .htaccess. Here is what I need.

WHEN URL IS THIS

www.mysite.com/cat/2011/subcat1/subcat2/product.htm?page=2

IT SHOULD 301 REDIRECT TO THIS

www.mysite.c开发者_StackOverflow社区om/cat/2011/subcat1/subcat2/product/2.htm

Can you please tell me how to do this?

Thanks

----- EDITED AND TESTED ANSWER ----------

RewriteEngine On
RewriteCond %{QUERY_STRING} page=(\d+)
RewriteRule ^cat/(\d+)/([^/]+)/([^/]+)/product\.htm http://www.mysite.com/cat/$1/$2/$3/product/%1.htm? [R=301,L]

• RewriteRule matched only the url part, not the query string. So, RewriteCond is used to match query string.
• Please note, matches from the url are used as $N and match from the query string is used as %N
• There is a question mark placed in the end of the rewritten url. This prevents the original query string to be added to the new rewritten url.

For any number of subcats:

RewriteEngine On
RewriteCond %{QUERY_STRING} page=(\d+)
RewriteRule ^cat/(\d+)/(.+)/product\.htm http://www.mysite.com/cat/$1/$2/product/%1.htm? [R=301,L]