Oh dear - from what I remember this is a pain in the ass of a job. Someone will hopefully correct me but I think what you are describing IS the oil filler - you top it up using some sort of gun thingy that pushes the oil in. I think someone on here had some success with a water bottle that had a tube on the end.
done it ! i bought a cheap bottle of oil with a filler tube, which i emptyed and used this to pump in the good stuff, draining plug is to the left hand drive side, filler just above the probe to the left. cheers guys