If I'm DNC'ing I queue up the program (I use a very old DNC program) press DNC, then Auto, then Start.
If it has a DNC button, then I would presume it has the option, mine lits up (not brightly though) the bulb in yours may be u/s.
I read in one of your posts you have a LeBlond Makino RMC 55 and you DNC to it. I have the same machine and was curious how you go about the process of it on this machine. It has the DNC button but when I press it it doesn't light up. Was hoping you could help me out. Any info would be greatly appreciated. Thank you in advance.