What is right rewrite rule?

I need a rewrite rule from this url (first) ?lang=rus&menu=about to this (second) /about_project/.

I currently have this .htaccess file:

Rewrit开发者_开发百科eEngine on
RewriteBase /
RewriteRule ^about_project/$ index.php?lang=rus&menu=about [L]

But this redirects from second to first, I need a rule for first to second!

RewriteRule ^[/]about_project/$ index.php?lang=rus&menu=about [L]

You should be looking for a / at the start.

You can use this tool:

http://www.generateit.net/mod-rewrite/

It's very useful.