I think what you're asking for is to check if the local player is within a certain area? If so:
Code:
Player pl;
Area a = new Area.Rectangular(new Coordinate(0,0,1), new Coordinate(5,5,1));
if((pl=Players.getLocal())!=null && a.contains(pl)) {
//player is in area a
}
Where Area a is outlined by bottom left coord (0,0,1) and top right coord (5,5,1).