Hi, I'm looking for SGEOID09 geoid model in. gtx format in order to custom add that height grid in CC. Anyone know where to get the geoid model from? Or perhaps using ggf or gdf? or other methods which can do so. Thanks.

If you do any work with these, you should really take the time to read the U.S. Coordinate Systems in MicroStation V8i and Bentley Map V8i article...