Can you explain your problem a little in detail? I am not sure if I understood the meaning of calculating the direction of two points. A point does not have a direction associated with it. It is just a point.
http://www.mathsisfun.com/algebra/trig-finding-angle-right-triangle.html
Get the change in x and y for the 2 points, and use trigonometry to calculate the angle.
You may have to offset the angle to account for North being 0.