Simple hook location and DB question. Please help!

[connkid25]

I have done most of the work but I know two things in this code are wrong. I am using vb 3.8.7 PL2. I need the online list to keep an IP. I have it working but when you go to a new page, the real IP shows. I am guessing either the hook is wrong and/or the area where it says $host. I had this working perfectly in the past but I cannot remember how I did it. The code is below. Any help would be greatly appreciated.

<plugin active="1" executionorder="5">
<title><![CDATA[Let us hide the ip of the superadmin.]]></title>
<hookname>online_query</hookname>
<phpcode><![CDATA[global $vbulletin;
$sadminid = $vbulletin->options['superadmin_id'];
if ($vbulletin->options['bogus_ip_enable'])
{
if ($vbulletin->userinfo['userid'] == $sadminid)
{
$host = $vbulletin->db->query_write("
UPDATE " . TABLE_PREFIX . "session
SET host = '" . $vbulletin->options['bogus_ip'] . "'
WHERE userid = '" . $vbulletin->options['superadmin_id'] . "'
");
}
}]]></phpcode>
</plugin>