XF 1.4 querystring for regisration

[Roka]

I make landing page with few buttons who links to xenfor registration form, but i need make querystring for all buttons.
ex. http://forum.test.com/index.php?login/login&btn=button1, http://forum.test.com/index.php?login/login&btn=button2 e.t.c

Then autocomplete custom field with querystring value. But if try to registry without querystring just http://forum.test.com/index.php?login/login redirect to landing page test.com

It is possibility to make? any idea?

Thank you to all

 

[Roka]

any to help me?