Hey Puff, unfortunately modifying playing data is limited to a site admin options, so it probably won't happen. The location is calculated by your IP address when you connect to servers.
Actually, unless I'm thinking of the old HLStats, there might be a couple in-server commands that can be used to change some of the GameMe info. I'll take a look this evening and edit this with what I find.
However, as far as location, like the two posts before me mentioned - it tries giving an estimate location, depending on where you play from. It's possible it may be choosing another country that has a city with the same name as one near you, but from my experience it tries picking the closest location it can (Also, like Steam, it doesn't have all the cities in the world stored in its database, just most of the major cities.