[kh99]

You could create a plugin using hook forumhome_complete and this code:

$res = $vbulletin->db->query_first("SELECT COUNT(*) AS numberbanned FROM user WHERE usergroupid = 8");

$numberbanned = vb_number_format($res['numberbanned']);
vB_Template::preRegister('FORUMHOME', array('numberbanned' => $numberbanned));

and then in the FORUMHOME template use {vb:raw numberbanned}.

This does add one query to that page. You could eliminate that by calculating it once every so often and putting it in the datastore, but I think that would require editing forum.php to add it to the $specialtemplates array (unless someone else knows a way around that).