Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See page_maxonapi_getting_started_foundations_cinema_parameters.
Parameter: Source Character
CS_SOURCE_CHARACTER
Parameter: Target Character
CS_TARGET_CHARACTER
Parameter: Go to Reference Pose
CS_GOTORESTPOSE
Parameter: Transfer Mode
CS_SOLVERMODE
Parameter: Strength
CS_GLOBALSTRENGTH