Sean,
A quick and dirty that won't be machinist accuracy is turn a length that fits in your tool post holder on a 1x1. (use A hard hardwood like Hard maple, purple heart....)
Leaving a square section. Then saw a vee in the top.
Lay the drill bit in the groove. I usually set the height with the drill bit centered on the lath center. An angles with a protractor square.
This is accurate enough for drilling stool mortises in the legs and seat where "close" is good enough.