you'd have to edit the 'navbar' template
If the last thing in your quick links is 'who is online'. In the navbar template it probably says something like :
Code:
<td class="something">
<a href="yoursite.com/whoisonline">Who is Online</a>
</td>
I'd copy and paste that underneath and change the link and 'Who is Online' to whatever you want.
Always make sure you have a backup when editing templates!