Modrewrite Accross Domain

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /

RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

That's the wordpress .htaccess

I tried to change the .htaccess to explicitly tell thedomain name.

So,

PHP Code:

RewriteRule . /index.php [L] 

becomes RewriteRule . [url]

Then I tried copy the .htaccess to another domain. I thought I'll create a mirror. However, rather than a mirror, the http://anotherdomain.com/bla simply REDIRECT to [url]

How do I ensure that http://anotherdomain.com/bla display the content of [url]without redirecting?

Where can I learn more about modrewrite? Is there a more appropiate forum?