Hello how can I do to make a custom shield map icon for a city in skyrim? like MArkath , Solitude , Whiterun etc?

The map iconography lives inside the menu system's SWF files. If you use a flash decompiler you can view them. I'm not sure how to add new ones, but obviously it can be done.

I can perhaps open swf files if this is what is needed , but I have to save and so alter the ones of the Vanilla base or I can add new one just for my tasks?