Map editing

I have no ideea if this is possible but this is what I'm looking for:
Would it be possible to edit a map (the image itself) in a way that whatever I add to the image (lines , dots etc) Will show up on the mini-map ? If it is , please point me the files I need to edit. Thanks alot , and I'm sorry if this has been asked / answered before.

LE: Damn posted in the wrong section. Can someone move this to the proper section ?

the minimap should be here client/data/minimap as i remmber it been months i hope iam right , it should be there in folders named after the map id like cronus folder is 1000 like the id etc , u need dds viewer to view them .