Thank you very much for the information. It is very useful. I'm taking a look at both possibilities.
Regarding the second option you gave me:
you can just run through the list of vertices and find the one that is closest to your MNI coord
What file should I use to find the coordinates correspondence? Should I use [l/r].pial? Or maybe
[l/r].orig?
Do you think it is a good idea to load that file in matlab and look for the closest coordinates there, and see what vertex index those coordinates correspond to?
Thank you in advance.