Create a new plugin
Product: vBulletin
Hook: global_state_check
Plugin Code: (I added the IE6 and lower check since I had problems in the past)
global $template_hook;
$template_hook['headinclude_css'].='
<!--[if gte IE 7]>
<link type="text/css" rel="stylesheet" id="arrowchat_css" media="all" href="/arrowchat/external.php?type=css" charset="utf-8" />
<![endif]-->
';
$template_hook['headinclude_javascript'] .= '
<!--[if gte IE 7]>
<script type="text/javascript" src="/arrowchat/includes/js/jquery-1.3.2.min.js"></script>
<script type="text/javascript" src="/arrowchat/includes/js/jquery-ui-1.7.2.custom.min.js"></script>
<script type="text/javascript" src="/arrowchat/external.php?type=djs" charset="utf-8"></script>
<script type="text/javascript" src="/arrowchat/external.php?type=js" charset="utf-8"></script>
<![endif]-->
';