Think I answered my own question, at least one way of doing it.
Edit adv_portal template for the new mobile style. Replace all of it with:
Code:
{vb:stylevar htmldoctype}
<html dir="{vb:stylevar textdirection}" lang="{vb:stylevar languagecode}" xmlns="http://www.w3.org/1999/xhtml">
<head>
</head>
<meta http-equiv="refresh" content="0;url=forum.php">
</html>
Works great.