c++ model element coordinates

I have been trying to search/figure out how to interact with 3D model through code without any luck. Lets say I have a board with a frame and some fields. Position of these fields changes depending on texture loaded. A simple example would be chess board and pawn on top of it.

How should I get the coordinates of face below the field to place another model on top of it? I have been thinking about defining the coordinates of field position in texture, and than finding model vertices related.

I would be very thankful for help and advice where and what to search.