When a Geographic Coordinate System is selected in a DGN file, it is possible to modify the GCS by defining Coordinate System Modifiers. One of the possible transformations is the Helmert transformation. I would like to know how to read or set these through the MicroStation C++ API. I don't see any relevant members in the MstnGCS / BaseGCS class.
I have the similar question, for CONNECT. I do see a function for setting the parameters for an Affine transfromation BaseGCS::SetAffineParameters(), but 1) I'm not sure that you can define a Helmert transform with this function, and 2) the descriptions of the 6 parameters could use some more detail...