Wolfe,
I have a lot of Le Creuset pans etc. I feeeeeel your pain....
They make a cleaner; go buy some. Don't screw with this pan. Don't Ajax it, don't use a really abrasive scourer on it...don't scrub the living daylights out of it...go buy the cleaner. It's not cheap (but neither is that skillet).
The other thing I would suggest doing along with using the Le Creuset cleaner is to heat the pan with some olive oil in it - decent amount, not a pot full but not just a smear covering the bottom of the pan. The idea is that you are trying to soak the melted bits off using the hot oil. You may have to do both a few times (don't ask me how I know
).
Good luck - anyone who screws with my Le Creuset or Sillet pans is usually screwed over by me...
Cheers,
Lisa