CMS Made Simple Forums

Dont't know if you know it but there's an inofficial CMSms version on CMSms Forge (based on V 0.12) which has multilanguage support.

http://dev.cmsmadesimple.org/projects/multilang/

Perhaps these one can helps to destroy your problem  ...

If you're using mod_rewrite functionality, then the urls generated by cms_selflink will have the alias in them.

However, if you want to modify the default functionality for url generation, look at GetURL in lib/classes/class.content.inc.php.  Almost all URLs in the system are generated from that method.