Link specific to account

Hi again,

I'm wanting to add a link to the menus section of Easy Blogging.

I have the menus addon set up, but I don't see how to add a menu without the full URL.

If you take the account that is for 'Joe' on the site, the full URL for that is:
http://easy.moonworkspublishing.com/joe

The URL I need is the following:
http://easy.moonworkspublishing.com/joe/wp-admin/admin.php?page=woothemes

I've tried putting in /wp-admin/admin.php?page=woothemes as the URL for the menu item, but that just gives me:
http://easy.moonworkspublishing.com/wp-admin/admin.php?page=woothemes

That misses out the whole /joe/ part of the URL, which then gives an error message as it's trying to load in a menu item only available to the admin on the main site.

I've set up Multisite on a sub-domain easy.moonworkspublishing.com which then uses sub-directories.