I believe this is one of the most requested plugins 
I don't quite follow your code. Are you making just one comparison of the coord? then you're "protecting" too much - nothing to the east (or whatever direction it is) of this coord can't be touched. You're much better off using a cCuboid class for storing the coords - it can store two pairs of XYZ coords, sort them and then it takes just a function call to know whether a point is inside or not.
The docs on the cCuboid class should be up to date; however I'm thinking about adding more IsInside() function flavors - ones taking a set of three coords rather than a vector.
I don't quite follow your code. Are you making just one comparison of the coord? then you're "protecting" too much - nothing to the east (or whatever direction it is) of this coord can't be touched. You're much better off using a cCuboid class for storing the coords - it can store two pairs of XYZ coords, sort them and then it takes just a function call to know whether a point is inside or not.
The docs on the cCuboid class should be up to date; however I'm thinking about adding more IsInside() function flavors - ones taking a set of three coords rather than a vector.