Of course, this is a silly solution, but...

Since you can buy seperate keyboard parts... and if you don't mind a bit of drilling / replacing some keys with custom keys / manual fixing of damaged traces on the pcbs...

Just drill a hole in the keyboard, file it off, and buy a trackpoint module from ebay, It'd probably work well enough!

- - -

that aside, making an expansion card which has a trackpoint on it, or notching it into just above the keyboard area, would probably be the most doable options, without needing the company to catch up