If no resistor is available, I have gotten good results by placing a DC engine on the program track along with the DCC engine. You need program track that is long enough for both.
Oh I didn't know that Mike. I'll have to remember that. I built a 2 foot long program track on a nice piece of maple, stained it, blah, blah, blah. For the extra touch I put a 1k ohm resistor at the end that's switchable with a toggle.