What type of machine are you running? Haas has a command G107 called Cylindrical Mapping, probably other machines have the same. This maps Y axis moves onto the periphery of a part mounted on the A axis. The Y axis is used to position the A axis exactly on the spindle centerline and then the G107 converts Y motion into the appropriate rotation of the A axis based on the diameter of the part. The motion is programmed as if it where a Y axis move.