Take the greyscale heightmap that is created by earthsculptor. The editor createa a .map file and several .png images (a shadowmap, a colourmap, a blendmap and a heightmap). The heightmap is the first png image without any extension at the filename. You need ONLY this file for the beginning. You convert this file to pcx or bmp. Then you open MED (not WED) and import the heightmap using import terrain from image. You have to choose the vertexamount for the terrain play around with this until you get the terrain in the right scale. Then you have to rescale the height of the terrain in MED if it doesn't look like it was in earthsculptor.