Unfortunately, it's been a while since I've played risk or used BGT. But hopefully this helps a little.
You could have a class called country with the following properties:
name of country
connected countries (as in an array of the countries that can be reached from this country)
current owner (as in the player who the country currently belongs to, if any)
army size (number of soldiers occupying the country, if there are different kinds of soldiers or something, you'll have to do this a little differently. Maybe a dictionary?)
Sorry about not giving you any code, but I really can't remember much BGT. I can't remember the rules of risk exactly, but hopefully this is cloce enough to give you an idea.
You could have the player select a country, and then have a menu of all the connected countries which they could choose from to move around the map. Does that make sense?