Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Mode
PH_SCENE_CAL_PLANAR_MODE
Parameter: Axis
PH_SCENE_CAL_PLANAR_AXIS
Parameter: Reverse Axis
PH_SCENE_CAL_PLANAR_FLIP_AXIS
Parameter: Selection
PH_SCENE_CAL_PLANAR_TARGET_SET
Parameter: Create Plane
PH_SCENE_CAL_PLANAR_CREATE_SCENE_PLANE
Parameter: Update Calibration
PH_SCENE_CAL_PLANAR_FORCE_EXPORT