For this you will have to utilize the Sitefinity Pages API and retrieve pages using the PageManager instead of binding the menu to a SiteMapDataSource. As far as I remember I have sent you a sample control illustrating how to achieve this in another support thread.
the Telerik team
Registration for Q1 2011 What’s New Webinar Week is now open. Mark your calendar for the week starting March 21st and book your seat
for a walk through all the exciting stuff we ship with the new release!