Go to admincp->Styles and Templates->Hit Collapse Templates button of your style->Navigation / Breadcumb Templates->navbar
Find:-
<!-- nav buttons bar -->
Add below:-
<td class="vbmenu_control"><a href="your file.php$session[sessionurl_q]">$vbphrase[your_phrase]</a></td>
Edit the above code as needed !! You may add more buttons in the same way ..