Uity3d project C# script

Hello, I need help with the following part of aUnity3D project. I require a radial knob of about 20mm diameter. (a simple 3d object is fine- I will replace it later) The knob must be turned via mouse drag starting on the circumference of the knob. Basically as the mouse is dragged arounded the knob the mouse rotates and a number output either decreases or increases depending if the knob is dragged anticlockwise or clockwise. The tricky part is that it needs to output 72 points for a full 360 degree clockwise rotation. So after it does 5 rotations it has a total of 360 points. At this point a further clockwise rotation should cause a reset to zero. If the counter was at zero and the knob was dragged anticlockwise it would go to 360 and count down. The example found at the address below, of the radial knob comes close to what I want but does not reset after 360 degrees plus does not have 72 points per rotation. ([login to view URL]) I would prefer the script to be in C# I am working with Unity#D 5.4.1 Many thanks Laurence