How to register user to a specific group if he choose one particular language?

[Demo16]

I want to register from the star a user to a particular group of users if he's using a specific language in the forum.

Example:

if I follow this link to register: http://www.xxxxxx.com/forum/register.php?langid=1
My registration form in EN

What I want is: every user that use this link for registration instead of becoming "registered users" becomes immediately "xxx users"

is this possible?

--------------- Added [DATE]1202315100[/DATE] at [TIME]1202315100[/TIME] ---------------

any help?