I'm designing a part with two v-grooves in which shafts will rest. The bottom of the v-groove will be relieved with a straight bit (similar to a standard v-block). Drawing the part in my CAD program is no problem, but when the drawing is converted to gCode, how do you specify the tool height and path relative to the contact point between the shaft and the groove?

Another way to ask the question is, how do you set the toolheight of a v-bit when you don't know how fine the point is?