This is an extender for the IBM/Lenovo ThinkPad series track point. I've used it for the custom DIY mechanical keyboard. Each extender has little different dimensions, so you can choose more preferred for you. And also, you always might use rasping for best performance.

Hello. I can't now remember all info about project, but I can send you the links from my Bookmarks for it https://geekhack.org/index.php?topic=8971.msg775152#msg775152 https://imgur.com/a/O6BdH https://geekhack.org/index.php?topic=55960.msg1269252#msg1269252 https://electronics.stackexchange.com/questions/155662/old-ibm-trackpoint-pin-scheme http://html.alldatasheetpt.com/html-pdf/19764/PHILIPS/PTPM754ADB/503/2/PTPM754ADB.html https://github.com/tmk/tmk_keyboard/wiki#flash-firmware https://github.com/tmk/tmk_keyboard/blob/master/tmk_core/doc/build.md

for focusing you in the right way: all track points are simple PS/2 mouses So you need to create PS/2 to USB converter by using teensy2 https://www.pjrc.com/store/teensy.html or, if you have PS/2 port in your motherboard, You can just connect TrackPoint to it. but maybe you will need some simple soldering with 2 resistors and one capacitor.

Good luck