You might get a better answer by posting this in the Custom Installers Forum. Please mention that you posted this here, though, just for reference.

There might be such a device, but as for being simpler: any device that does this requires quite a commitment of time and money to bring it to market, and I can't imagine such a thing would be as simple as you need. I'll bet most people who need it want at least a thirty command repertoire. The price and the complication could logically be seen as the price of admission for ANY such device. Imagine, in today's computer market, saying you need a device for writing term papers, but you don't need the fancy capabilities of Word, nor a computer as fast as today's models, not even a color screen. But nobody makes such a product! You have to get something much more capable to get anything at all.