The mds file works in some sort of coordinate system in conjunction with the MT_COMMANDBAR dds (or maybe the COMPRESSED tga) file to locate and display icons. Since the units refer to them by name and not coordinate, and we can't edit the mds, we can put new icons in the commandbar file but we don't know how to locate them. But, once we can use and edit with mds, or at least figure out the coordinate system, then it'll be easy to add new icons.