This really doesn't have anything to do with the geck, but it is relevent to modding fallout 3, so here we go!

I am aware that with TESannwyn, you can export heightmaps from oblivion, but can you export heightmaps added by mods? The reason I ask is because I would like to use the D.U.N.E worldspace in my upcoming TC for fallout 3, (don't worry, already asked for permission, waiting for feedback.)
and how would I do this? Also, how would I completely retexture the land easily, and quickly?

Thanks.