Lathe Speed Control

Hi,
I have Baldor DC motor adjustable speed controller, that has a speed
pot.
I have a 3 in 1 lathe that i want to control the speed for Constant
Surface speed (CSS).
My question is would it be possible to change that speed pot to a
Digital pot and control it with Mach 3 Turn or Turbocnc4? Is there
another
way to use the Baldor speed controller with Mach 3 Turn or Turbocnc 4?

Thinkcnc
Bob A
http://stcnc.tripod.com/