[Dismounted]

You need to do something like this:

PHP Code:

<?php
// current directory
$curdir = getcwd();

// switch to vbulletin directory -- CHANGE THE PATH
chdir('./your_forum_path/');

// include global.php
require_once('./global.php');

// run functions
build_language(-1);

// switch back directory
chdir($curdir);
?>