1/2" to 1/4" dowel reference pin

My self-centering dowel jig has 6 different dowel size options, but I wanted a way to use one of the holes to reference another hole so everything could be perfectly evenly spaced. This would allow me to just use this reference pin to drill out my dowels on both mating pieces, and so long as I start the same distance from the edge, it should match perfectly.