Controlling an RC car with the NXT

[zapper9987]

So, my goal is to use the NXT to control my RC car, but I am not sure how to do this properly or if it can be done at all. Right now my goal is just controlling speed.

Here is a picture of the setup and how it works:



As you can see, the battery puts out around 8 volts into the speed control, witch controls the motor. The speed control puts out about 5.5 volts in to what would normally be the remote receiver. The receiver would read the signal and put a percentage of the positive back into the speed control through the wire labeled "input".

Now, I would like the NXT to control the speed not the remote signal receiver. Is this possible, and if so, how would I go about doing it? (I'm using leJOS on my NXT, obviously )

Thank you, and if I posted this in the wrong forum, I apologize. I wasn't quite sure if it would classify as a project or a hardware related thing.