If your unparsed text is in $unparsed_text, to parse it into $parsed_text:
PHP Code:
require_once(DIR . '/includes/class_bbcode.php');
$bbcode_parser =& new vB_BbCodeParser($vbulletin, fetch_tag_list());
$parsed_text = $bbcode_parser->do_parse($unparsed_text);
For details on extra arguments for do_parse(), controlling whether to parse HTML, image links, url's etc, see the API doc at:
http://members.vbulletin.com/api/vBu....html#do_parse
-- hugh