Just to expand on my comment above, here is an approach that may work for you: Fake it :)
When you launch the program, intercept all windows messages to the program that control it's position on screen. That way it 'appears' to be fixed in place, but in reality it's still attached to the normal Windows desktop.
Here's some light reading for you:
A hook is a mechanism by which an application can intercept events, such as messages, mouse actions, and keystrokes. A function that intercepts a particular type of event is known as a hook procedure. A hook procedure can act on each event it receives, and then modify or discard the event.