dial up 121.5, squawk 7700 and shout for help (PAN call)
I somehow think that D&D would appreciate an "unsure of position, request fix" more than a full-blown emergency squawk with a PAN call and everything.
You need to realize that as soon as you squawk 7700, all ATC units that have you on radar, including those that you're not talking to, will start watching you and start clearing the airspace around you, particularly below you. Maybe some rescue units near you will get a heads-up call for a possible emergency landing. After all, from your squawk alone they can't figure out that you only need a position fix from D&D, and are talking to D&D to achieve that. So they'll fear the worst and act accordingly.