C3D added the drill path but drilling on a CNC is problematic. I would agree with Michael Hotchin that a pocket tool path would work better.
Just curious, why are you making dog holes in your spoilboard?
I have a Shapeoko 3 XXL and made my spoilboard with 1/4-20 Tee Nuts. I use cam clamps and L brackets to line up material. You did not say what type of machine you have but I have a document I created for the SO3 but is applicable for all machines.