Friendly URL with i18n

Hello,
Need help setting up routes.
I use i18n multi language routes look like this:

PHP Code:

$route['^(de|en)/(.+)$'] = "$2";
$route['^(de|en)$'] = $route['default_controller']; 


I have address:

Code:

en/articles/category/category-name

and I would need

Code:

en/category/category-name

of doing this?

Sorry for my bad English, and thank you in advance