Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Tone Mapping
ID_PV_FILTER_TONEMAPPINGParameter: Saturation
ID_PV_FILTER_SATURATIONParameter: Brightness
ID_PV_FILTER_BRIGHTNESSParameter: Contrast
ID_PV_FILTER_CONTRASTParameter: Exposure
ID_PV_FILTER_EXPOSUREParameter: Gamma
ID_PV_FILTER_GAMMAParameter: Red
ID_PV_FILTER_REDParameter: Green
ID_PV_FILTER_GREENParameter: Blue
ID_PV_FILTER_BLUEParameter: Invert
ID_PV_FILTER_INVERTParameter: Black Point
ID_PV_FILTER_BLACKPOINTParameter: White Point
ID_PV_FILTER_WHITEPOINTParameter: Grading Intensity
ID_PV_FILTER_GRAD_INTENSITYParameter: Curve Min
ID_PV_FILTER_GRAD_MINParameter: Curve Max
ID_PV_FILTER_GRAD_MAXParameter: Curve
ID_PV_FILTER_GRAD_SPLINE_RGBParameter: Red
ID_PV_FILTER_GRAD_SPLINE_RParameter: Green
ID_PV_FILTER_GRAD_SPLINE_GParameter: Blue
ID_PV_FILTER_GRAD_SPLINE_BParameter: Reset Values
ID_PV_FILTER_RESET