vars in config / route.php

Hi I am creating a website in more languages. I have 9 maingroups in 4 languages.

I want to create (if possible) something like this:

$route['(women|men|shoes|kids|bodywear|eyewear)']='maingroups';

But I want to put the string 'women|men|shoes|kids|bodywear|eyewear' as a varibele. But I cannot find if it is possible to do something like so:

$maingroups=array();
foreach ($tree as $node) {
          $maingroups[]=$node->cat_name;
  }

$pages = implode('|' , $maingroups)
$route[$pages] = 'maingroups';

Can someone help? Thanks and kind regards.