[bpr]

According to the file register.php in your forum root directory this is line 17:

PHP Code:

define('THIS_SCRIPT', 'register'); 


You can also use "THIS_SCRIPT" to ask for the current script, in that case you could say

PHP Code:

if (THIS_SCRIPT == 'register') { do this} 


i am not an expert on the hooks but i assume that you could actually create a new plugin choose the right hook and then you just put your if clause which i mentioned before and afterwords you do something like this:

PHP Code:

$template_hook['YOU NEED THE CORRECT HOOK'] .= vB_Template::create('header_include_orwhatever')->render(); 


hope it helps