Registration and User group

[Zhadum 1]

Hi,

I'm looking for a module which allows a customer-to-be to join a user group (already created in the BO) when filling the registration form, just by entering the name of the group he wants to join in the registration form.

Any ideas (even in paid modules)?

There are modules that automatically do that ("Acccount Group" module ) but thing is I don't want the user groups list to be visible...

Thanks!