I think the title says all. My map is nearly empty now because too much miners mined to much. So I would like to select regions and recreate Ores without deleting caverns. It would be simply replacing blocks in the region with 80% Stone 8% Coal 6% Iron 4% Diamond 2% Gravel and dodging "air". I cannot pay for this, but I think it could be useful to many more than myself. So, If you're interested
what //regen does is it determines the chunks that are partly inside the selection then, for each chunk, it saves everything outside the selection, regenerates the whole chunk and puts the saved stuff back in. this usually means your stuff is still there. However, as of worldedit 4.7, this still makes doors pop off and causes some other effects.