mouse – Synaptics PS/2 driver over USB

I have a physical disability that makes it impossible to use a computer normally, and the only thing that works for me is the Synaptics Touchstyk mouse, which is similar to trackpoint. It only comes on certain laptop models, and I’m having trouble finding one that meets my needs, plus they’re usually the more expensive business models. So I want to remove it from a laptop so I can use it on any computer.

Anyway, I have the pinout for the ribbon cable that attaches to the motherboard. The interface is PS/2. So I could make a PCB that converts it to a PS/2 connector, and I’ve done enough experimenting to know that will work, and then I used a USB adapter. That works, but the Synaptics driver uses some proprietary PS/2 protocol which gives it more detailed data on the force applied to the sensor, which allows it to be it much more sensitive. I need that high level of sensitivity.

I don’t think I can just use the Synaptics driver on the USB to PS/2 adapter, it needs to interface with the raw PS/2 protocol. Is there some other way? Is there a USB to PS/2 adapter that looks like a PS/2 port to the computer? Or some way for the driver to work over USB?

Thanks for any ideas, or where would be a better place to ask this question.