Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Use Transfer
ID_TAGFIELD_ENABLEParameter: Transfer Mode
ID_VERTEXMAP_TRANSFER_MODEParameter: Invert
ID_TAGFIELD_INVERTParameter: Use Deformed Points
ID_TAGFIELD_DEFORMEDParameter: Fields
ID_TAGFIELDS