3 speed conversion?

[pat english]

I was wondering if anyone might have info or links about converting a 3 speed column shift into an automatic style steering column?I found a bunch of info on converting the 3 speed to a floor shift,but nothing on converting to an automatic.I know it can be done.An old timer who was helping me out with my engine build said there easy to convert and That was a popular conversion back in his day.But he recently died.Thanks,pat