There is unfortunately no easy way to do this, if at all. However, on many 15" to 17" laptops the keyboard can sit snugly over the existing one without causing any trouble. You would have to move it every time you open/close the laptop of course so it's not an ideal solution, but workable without losing desk space.

We've actually looked into getting this done in the past, but unfortunately virtually every laptop keyboard has a slightly different layout making this virtually impossible for us at this time.

-TypeMatrix

I've used the keyboard quite successfully by simply setting it on the laptop keypad. I could even use the trackpad beneath the TypeMatrix quite easily. There were some issues with the TypeMatrix feet pressing keys on the keyboard, but all-in-all very do-able.

Totally agree with KoreyPeters.

Soon after I got my EZReach 2030, I started using it by laying it on top of my Thinkpad's keyboard. It rarely presses any keys underneath AND I can still use the touchpad.

It would be nice though if TypeMatrix would make a small, thin support piece that sat along sides of laptop keyboard and elevated the TypeMatrix keyboard just a tad off the laptop keys.

If you use *nix, you could write scripts to disable and re-enable the built-in keyboard (forgive me for suggesting something I don't yet know how to do). This thread looks promising:
http://unix.stackexchange.com/questions/39663/how-to-disable-laptop-keyboard-on-plugging-in-a-usb-keyboard
Good luck!
-k