Can you please explain in more detail what you are looking for?
Are you trying to enable overflow in an HTML app? In a Xaml app? If you let us know the details we can get you to the appropriate forum.
The default behavior in Xaml will be similar to HTML's overflow=hidden.
It would help if you could provide sample code demonstrating what you are currently doing and an explanation of the desired behavior and how it is different from the actual behavior.
--Rob