the trouble i'm guessing you'll face is that all the map data is stored separately from the maps themselves, the graphics, and the AI nodes for pathing. structure is somewhat similar to:
[.MAP File]contains (L*W*H) tile entries, each with potential references a floor, a north wall, a west wall, and an object.
[.MCD File]numeric data table, 61 bytes per entry. floor/wall/object references in the map file refer to entries in these files. MCDs also contain references to corresponding .PCK/.TAB files with the terrain sprites. these are referred to by the map sequentially based on file order.
also contains references to scang.pck for the minimap sprite and loftemps.dat for the 3d representation of the object.
[.RMP File]a database of nodes on the map, containing info on unit spawn positions and patrol destinations. generally used by the AI to make its way around the map before XCom is discovered.