Have you tried using mypage. It's essentially a blank module that allows you to post static PHP/HTML content in a page. In the xoop_version.php file, you can easily assign sub-menus and point them to wherever you wish. It's extremely simple to duplicate and rename as well. When I've run into situations where I couldn't find any other module that would work for my needs, it was a life saver. I'm not sure if mypage is available on sourceforge, but it's extremely simple to code. You can find more information about it in Xoops for Dummies at the Xoops Documentation Site.
Another module that offers a little more control over your content is Tiny Content Duplicable. You can download that module from sourceforge and there is documentation on it at the XOOPS Documentation Site.
Hope this helps.