[kh99]

Well, you could try creating a plugin using hook location forumdisplay_complete and code like this (change the X on the first line to the id of the forum where you want it to display):

PHP Code:

if ($forumid == X)
{
   if ($result = $vbulletin->db->query_read_slave("SELECT * FROM " . TABLE_PREFIX . "user WHERE usergroupid=20 ORDER BY username"))
   {
      while ($user = $vbulletin->db->fetch_array($result))
      {
         $members[] = $user;
      }
      $template = vB_Template::create('my_memberlist');
     $template->register('members', $members);
     $template_hook['forumdisplay_below_threadlist'] .= $template->render();
   }
} 


then create a new template something like this:

Members:<br /><br />
<vb:each from="members" key="key" value="member">
<a href="{vb:link member, {vb:raw member}}">{vb:var member.username}</a><br />
</vb:each>
<br/><br/>

In this example I named the new template 'my_memberlist', but you can name it anything you want as long as you change it in the plugin code as well.

Of course this is a simple example, html isn't really my thing so I'll leave it up to you to make it look good.