a filter for before parsing the query string

hi there!
there is a filter for modifying the category_link. as much as i know, it is possible to change the link in anyway one wants.
i have added support for multilingual links as follows:
/LANG_SLANG/category_link
but there is a little problem with when parsing the query. there is a filter to check and manipulate the query string but it’s after when the wordpress decides what’s what; which causes problems with parsing the data. i had to add a filter to the WP::parse_request at line 184 to make it possible to change back the query to the way it should be:
184:$request = apply_filters( ‘pre_parse_query’, $request);
185:$this->request = $request;
i was wondering if it’s possible to add this to the wordpress project; since it is possible to change the query any way we want; and hence we need to have a way to make it wordpress readable again…
would you please tell me if and how such a feature can be added to the wordpress core?
thanks in advance…