Virtuemart 2 Registration - Gantry Template assignement

[cpt_avatar]

Hi,
I'm developing a Multilanguage website with Joomla, and VirtueMart 2.

I choose to leverage the Virtuemart registration form instead of the standard Joomla registration form (much easier integration).

Here the issue:
I need to assign a Gantry EN template to the registration form instead of the default one, or I get an error as the menu is not the correct language.
I usually create an "hidden menu" with the template assignment, but DOES not work with the registration form as does not exist a Menu for Virtumart registration form.
I also tried with "external link" but does not work.

Can someone help me ? Thanks ! really appreciated !
Andrea

Site: Joomla! 2.5.11
Virtuemart: 2.0.26d
Gantry v4.1.18

[cpt_avatar]

Anyone can help me ?