Birth country can't be changed yet. The way it is stored seems to be offset based or something, like the player names. Haven't figured it out yet. Date of birth is in the exported spreadsheet.
Feel free to write tutorials and stuff to help eachother out. I had planned to do it but gave up. I realized it is better to just get it out so you can try it. I have not tested my changes on 2K10 yet so I appreciate feedback.