.vc files are separate from maps. You create them with the same name as your mapfile, with function names that reference your zone or entity script names.

For instance. If you made foo.map, you can create foo.vc for that map. If you put a zone on the map, and make it's activation script named my_zones_script, then in the vc file you should do:

function my_zones_script() {
//this executes when someone activates the zone on map.
}

If you want to switch maps, Map("Foo.map"); does the job. Try putting it in Zones!

Here's a longer thread on mapswitching:
http://verge-rpg.com/help/map-changing/

Yup. Simple as that. :) The .vc extension is just a name, you don't need any kind of special program to type it up.