Doug,
Breaking it down to its core:
{if $usertype eq "A"}
(easy enough)
{include file="modules/Users_online/menu_users_online.tpl"}
{/if}
got it?
Where you can have some fun -- MOVE the include from its default location in /skin1/rectangle_bottom.tpl - where you'll need the {if $usertype eq "A"} to filter out the customers -- TO head_admin.tpl -- which will only be visible to admins (you will or you have locked down your /admin direcrtory at your server, yes?
Here's where I put it (in head_admin.tpl)
Code:
<table cellpadding="0" cellspacing="0" width="100%">
<tr>
<td width="650">
{include file="modules/Users_online/menu_users_online.tpl"}
</td>
{if $login ne ""}
<td align="right">{include file="authbox_top.tpl"}</td>
<td width="10"><img src="{$ImagesDir}/spacer.gif" width="10" height="1" alt="" />
</td>
{/if}
</tr>
</table>