I know you said that there is a touchpad on the laptop, but could you cover the touchpad with some tape and a flap so that it wouldn't accidently get hit? If I have the right mental image in mind that would protect the touchpad from sensing unwanted input, and the worst thing that may happen would be that a mouse button me be pressed.

However before doing that I would check to make sure that when the laptop was closed whatever you put there wouldn't touch or be able to scratch the screen.

One last thought... have you looked into voice recognition products like dragon dictate or IBM's ViaVoice. I am not certain if these products are supported for languages other than English, but typically you can train them for at least simple phrases to do basic commands. Even though they may be English products you might be able to trick them into still working. If you could do that you may be able to vastly increase your range of input.