1,send the application to background.
2,Display a RWindow at desktop.
Can i do that???
You can send your application to Background.
You can capture RWindow screen using api CopyScreenToBitmap. refer here
For Displaying it on Desktop, you will need to do some serial communication and then render the image on desktop.
"Dare To Dream" - A.P.J.Kalam
Also I could suggest you to check these articles in Wiki:
Drawing to the screen outside application frameworkHow to display ticker on active idle + example application