Auto Fill CB User Registration USERNAME Field with data from another form?

Hello,

Is it possible or is there a CB plugin available that allows you to auto fill the CB registration "username" field with data from another form. For example: With Fabrik you are able to re-use data from another form and auto fill the "username" field of the juser registration plugin by using the PHP below.

$session =& JFactory::getSession();
$uid = $session->get('name');
return strtoupper ($uid);

My question is: Is it possible to do something similar with the CB user registration form. And once the field filled it should be marked read-only?

Thank you
P.