I think you will need to BORE the hole for accuracy .
SO you need to determene how you are going to mount the part compared to the axis. Will you be inline to the X axis or Y axis with the boring bar. That will set your Plane as either XZ or YZ. Next figure out if you are in the Positve side or neg side of the plane, left or right of zero.
Then you would get every thing set and select G18 0r G19 plane then center the hole and use a boring canned cycle just like you would do in a vertical mode.
NOW the canned cycle is only good in the POSITVE side of the plane SO IF you find yourself on the NEG side you need to invert the axis by changing the scale from +1.000 to -1.000.
It is just a little strange using different axis in the canned cycle call NAD if you invert teh axis the depth call will be backwards
Sample G81 Z0.000 Y0.000 X1.000 R0.000 F3 THE ZY is the hole position and the X will be the depth.
It would go to Y0Z0 and X0.000 then slow feed down into the hole to depth then retract back to X0.000
Hope that helps, Let me know if you need more info.
(;-) TP