2300MP USB Support

I bought this projector a few years back and have just used it as a display device with the remote control. Now, I would like to control it via the USB i/f. The documentation says nothing about USB other than there is a connector. When I connect the 2300MP and look at Control Panel->System->Device Manager I see that Windows XP detects the USB device as a "USB Human Interface Device" and more specifically as a keyboard device. What's with this? Is there some sort of utility available to control the projector? Does it simply accept command strings and that's the extent of it?

Any advice is appreciated.

Thx