Create a custom projection

Discussion created by mcollins999 on Dec 2, 2011
Latest reply on Dec 21, 2011 by mcollins999
How difficult would it be to create a custom projection with a grid shift and a rotation?
I have shape files from a mine site and they used their own mine grid. I've been given a diagramme (see attached) that shows the grid shift and rotation of their mine grid with respect to a UTM grid (I changed the coordinates for privacy). I need to create a projection based their mine grid so I can use their shape files. Any ideas?