Check For A URL's Top - Level Domain In C#?

how do I fetch "fr" out of this? JUST "fr" actually what I am trying to do is change masterpages at runtime after detecting a visitor's country..Yes I can use the countryCode variable which is there in some other class but thot may be I can do it like this only..just wanted to try..logic basically is:-

if(its "fr")
{
//apply masterpage 1
}
if(its "in")
{
//apply masterpage 2
}

Is it possible ? What will be the right way anyway ? Making that class that contains CountryCode variable as a utility class and using the variable from there in my new class OR fetch this value "fr" or "in" off the URL ?? How do I do this ? Is it possible?