hfss relative coordinate system

How do I create a relative coordinate systems in HFSS. The coordinate system should rotate the XY plane 45 degree around the z axis?

Press to coordinate buttons in the top bar. HFSS is really stupid when it comes to coordinate systems, you sort of have move the axis manually or type in the coordinates that makes 45 degrease turn.

If you have the possibility then use CST MWS it is better and more user friendly EM solver.