Rewrite url or use routing

[eluser]0v3rth3d4wn[/eluser]
Here is my route.php

Code:

$route['default_controller'] = "home";
$route['404_override'] = '';

// URI like '/eng/about' -> use controller 'about'
$route['^(bg|eng)/(.+)$'] = "$2";

// '/eng' and '/bg' URIs -> use default controller
$route['^(bg|eng)$'] = $route['default_controller'];  

//here first I try to get rid of the index but something isn't just right and it is not working...
$route['(bg|eng)/category/:num/:num'] = "category/index/$3/$4";