Language switching : Process variable and "redirect" to current_url()

[eluser]bonatoc[/eluser]
OK, so I'm somewhat less a newbie than 2 hours before.

After doing some RTFM_ing, I ended up with this, in config/routes.php

Code:

$route['(:any)/changelang/(:any)'] = '$1';

But since I struggle with Regex's, could someone tell me if this will work no matter where "/changelang/" is located in the URL ?

What I mean is : Is this expression valid for ALL the following URLs ?

http://mysite.com/admin/changelang/de-utf-8
http://mysite.com/products/detail/59/cha...g/de-utf-8
http://mysite.com/products/changelang/de...detail/59/

Also, is there a simple way to clean
current_url()
or
SELF

to avoid double declarations ? Like :
http://mysite.com/admin/changelang/de-ut...g/de-utf-8

I guess I could pass the URI segments to my View and do some substr from SELF .

Thanks !