Brett,
I'm not 100% sure, but I don't think you can use a controller with the demo. When the full Real Flight is installed you have to use the controller that comes with the software. If you want to use your own radio with that you have to plug your radio in to the Real Flight controller in order for it to work. There is no way you can plug your own radio directly in to the computer. I'm pretty sure that would apply to the demo as well.

Ken