Redirect from one url to another. Qtranslate and search engine problem

Question

I've changed my qtranslate configuration. I access to the english version now with:

http://en.mydomain.com/news/this-is-a-post

In search engines I have my pages indexed with this structure:

http://mydomain.com/news/en/this-is-a-post

I've tried adding these in my htaccess, but they are not working:

RewriteRule ^en/(.*)$ http://en.mydomain.com/news/$1 [R=301,L]

and

RewriteRule ^news/en/(.*)$ http://en.mydomain.com/news/$1 [R=301,L]

This is my entire htacess:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /news/

RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /news/index.php [L]

</IfModule>

Any idea how to do this ?

Thanks!