Im trying to get CEON URL working with Multi-language SEO URLs (http://www.zen-cart.com/downloads.php?do=file&id=1717).
By adding:

RewriteRule ^(en|es)/.* index.php [QSA,L]

to the htaccess file ("en" for english and "es" for spanish) the index pages seems to be working fine but all other pages gets a "Page not found error". I suspect the reason is that "Multi-language SEO URLs" adds the "en" and "es" directories to the URL like this:

www.mywebsite.com/en/
www.mywebsite.com/es/

Is there a way to add a rule in htaccess to solve this problem? Or would the code in the CEON module need to be modified?