Deckel fp4a diagonal machining

I need To drill and tap holes to 18 pieces of aluminium angle bar which is longer (711mm) than my Deckel FP4A x axis travel but it can be done diagonally with x and y axis.

How should i approach this and program the machine? Can i locate edges/corners with edge finder and get the points for the control so it can determine the angle it is clamped to?

Or do i need to do it manually and calculate the angle and use coordinate rotation g code?

The machine is with Grundig contour 3 control which is similar to Dialog 4.

Thanks! :)