Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See page_maxonapi_getting_started_foundations_cinema_parameters.
Parameter: Frame Dependent
GV_PYTHON_FRAME
Parameter: Reset on Frame 0
GV_PYTHON_RESET
Parameter: Code
GV_PYTHON_CODE
Parameter: Open Python Editor
GV_PYTHON_OPENEDITOR
Parameter: On
GV_PYTHON_ON
Parameter: Integer
IN_LONG
Parameter: Integer
OUT_LONG
Parameter: String
IN_STRING
Parameter: String
OUT_STRING
Parameter: Float
IN_REAL
Parameter: Float
OUT_REAL
Parameter: Vector
IN_VECTOR
Parameter: Vector
OUT_VECTOR
Parameter: Matrix
IN_MATRIX
Parameter: Matrix
OUT_MATRIX
Parameter: Time
IN_BASETIME
Parameter: Time
OUT_BASETIME
Parameter: Bool
IN_BOOL
Parameter: Bool
OUT_BOOL
Parameter: Link
IN_LINK
Parameter: Link
OUT_LINK
Parameter: Filename
IN_FILENAME
Parameter: Filename
OUT_FILENAME
Parameter: Gradient
IN_GRADIENT
Parameter: Gradient
OUT_GRADIENT
Parameter: InExcludeList
IN_INEXCLUDELIST
Parameter: InExcludeList
OUT_INEXCLUDELIST
Parameter: SplineData
IN_SPLINEDATA
Parameter: SplineData
OUT_SPLINEDATA
Parameter: SoundData
IN_SOUNDDATA
Parameter: SoundData
OUT_SOUNDDATA