if its movement is periodic, ie, it moves from side to side without falling down some other oriface, may i suggest a method that has worked OK for me. i carry the metal and magnetic grabbers that people upthread mention in my toolbox in my trunk, and would suggest trying those first. if you can't get one of those, take a length of moderately large diameter vacuum hose, longer in length than the dash so that it can't fall down the hole like the pen hook it up to a shopvac or other substantial source of suction by reducing with duct tape, et cetera. stick it in there, and put a decent length inward until you achieve contact. repeat the contact process until you can acquire it visually, and use a stick with a blob of tape to finish things up and pull the pen out. perhaps this will be helpful to you in some way.