To tell you right off you would be looking for a .cpn file in the data folder. There is also an .XMB file in there too that matches the name of the .cpn file.
I looked at the .cpn files and knoticed it would be possible to edit them, if you knew what stuff to type in.
The .XMB file is a different matter, because it is written with symbol type charactures. (Which I would not know how to edit those...)
The .cpn file has a little thing at the begining which looks to be the stuff for the map. Further down is what looks like a list. Contained in that list is several bunches of lines, each with the name of the senario, short description, and also what I believe to be an object placer on the main map.