yup, 2 ways to do this.
1) manually add the link, open wrapper.html and find the 3 current links and add yours as illustrated below:
PHP:
<div id="topmenu">
<ul>
<li><a href="{$list_url}/">{$lng->main_menu_rankings}</a></li>
<li><a href="{$list_url}/{$url_helper_a}join{$url_tail}">{$lng->main_menu_join}</a></li>
<li><a href="{$list_url}/{$url_helper_a}user_cpl{$url_tail}">{$lng->main_menu_user_cp}</a></li>
<li><a href="http://YourLinkURLhere">Your link text</a></li>
the second alternative is to use the "menu manager" instead:
open wrapper.html and replace this:
PHP:
<ul>
<li><a href="{$list_url}/">{$lng->main_menu_rankings}</a></li>
<li><a href="{$list_url}/{$url_helper_a}join{$url_tail}">{$lng->main_menu_join}</a></li>
<li><a href="{$list_url}/{$url_helper_a}user_cpl{$url_tail}">{$lng->main_menu_user_cp}</a></li>
</ul>
with:
then login to your admin, and choose "manage menus" under "custom pages".
Next click "Create New Menu", and enter a name for this menu, perhaps "top"
Next click "Create New Menu Item" and add the 3 links you removed earlier, if your using clean URL's they would be:
Rankings -
http://yourdomain.com
Add Your Site -
http://yourdomain.com/join/
User CP -
http://yourdomain.com/user_cpl/
if your not using clean URLs:
Rankings -
http://yourdomain.com
Add Your Site -
http://yourdomain.com/index.php?a=join
User CP -
http://yourdomain.com/index.php?a=user_cpl
now you can easily add and arrange items in this menu from the admin panel.
if you have any questions, do not hesitate to ask.
*I'm hoping in the "Gold release" to have this menu moved into the menu manager, just need to sort out a method of dealing with the clean URL's settings.