Unfortunately there is two definitions of DNC, Distributed Numerical Control or Drip Feed, I assume you want the former, or both?
If so Cadem may fit the bill with some nice options that you may not need the dual mouse etc?
The operator can upload or download from his machine without touching a computer.
I don't know wether MicroTech simulator will fit the bill for you in the way of verification, but it is free.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.