Setting custom userfields

[squishi]

I am in the process of creating an additional registration step to my forum.
I want to set custom userfields in the register_start hook.

Here is what I have:

PHP Code:

//some code

    $vbulletin->input->clean_array_gpc('r', array(
        'userfield' => TYPE_ARRAY,
    ));

    $userdata =& datamanager_init('User', $vbulletin, ERRTYPE_ARRAY);

    // set profile fields
    $customfields = $userdata->set_userfields($vbulletin->GPC['userfield'], true, 'normal');

//some more code 


My problem is that vb checks for required fields. I've tried using the set_userfields method with 'admin', 'normal' or 'register', but the result is the same.

So how do I set custom fields with regex verification (for security) but without checking if fields are required?