[Dismounted]

PHP Code:

// initialise bbcode class
$cwd = getcwd();
chdir('./forum/');
require_once('./global.php');
require_once(DIR . '/includes/class_bbcode.php');
$parser =& new vB_BbCodeParser($vbulletin, fetch_tag_list());

// parse message
$message = $parser->parse($yourmessage, $forumid);

// get back
chdir($cwd); 


Change directories and variables as appropriate.