Access Controlling a non Yii directory?

So, I have access rules working well for controllers and actions… but I have a PHPBB forum in a subdirectory that I’d like to restrict access to people that are logged in. Is that something that I can control with Yii or do I have to hack the forum code somehow?

/htdocs/index.php < ---- Yii starting point


/htdocs/forum <-- PHPBB forum

Thanks for any links or advice you may have. If I figure it out, I’ll post what I did. Thanks