How do I get Permanent Marker, black, out of a a polyurethane finished wood surface?

My wife was making posters, evidently the paper stock was thin enough to allow the maker to bleed through. Now one can read what she wrote on the polyurethane wood counter surface.

I had refinished the surface last summer and am hesitant to do the project again. We have tried alcohol and bleach neither has removed the letters, although the bleach seemed to cause the letters to fade a little.