Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See page_maxonapi_getting_started_foundations_cinema_parameters.
Parameter: Target Spline
FP_FOLLOWSPLINE_OBJECT_LINKParameter: Invert Spline Direction
FP_FOLLOWSPLINE_OBJECT_INVERTDIRParameter: Mode
FP_FOLLOWSPLINE_OBJECT_BEHAVIOURParameter: Rail
FP_FOLLOWSPLINE_OBJECT_LINK_RAILParameter: Invert Rail Direction
FP_FOLLOWSPLINE_OBJECT_INVERTDIR_RAILParameter: Use Closest Point on Rail
FP_FOLLOWSPLINE_OBJECT_RAIL_CLOSESTParameter: Mix
FP_FOLLOWSPLINE_OBJECT_MIX_FACTORParameter: Effect Radius
FP_FOLLOWSPLINE_OBJECT_RADIUSParameter: Source
FP_FOLLOWSPLINE_OBJECT_MAP_QUANTITYParameter: Source Scale
FP_FOLLOWSPLINE_OBJECT_MAP_QUANTITY_SCALEParameter: Segment
FP_FOLLOWSPLINE_OBJECT_MULTI_SEGMENT_MODEParameter: Segment Index
FP_FOLLOWSPLINE_OBJECT_MULTI_SEGMENT_CHOICEParameter: Attract Strength
FP_FOLLOWSPLINE_OBJECT_ATTRACT_STRENGTHParameter: Attract Falloff
FP_FOLLOWSPLINE_OBJECT_FALLOFF_ATTRACT_RADIUSParameter: Attract Map
FP_FOLLOWSPLINE_OBJECT_ATTRACT_STRENGTH_MAPParameter: Follow Strength
FP_FOLLOWSPLINE_OBJECT_FOLLOW_STRENGTHParameter: Follow Falloff
FP_FOLLOWSPLINE_OBJECT_FALLOFF_FOLLOW_RADIUSParameter: Follow Map
FP_FOLLOWSPLINE_OBJECT_FOLLOW_STRENGTH_MAPParameter: Align Mix
FP_FOLLOWSPLINE_OBJECT_ALIGN_MIXParameter: Exit Behaviour
FP_FOLLOWSPLINE_OBJECT_EXITBEHAVIOUR_CLOSESTParameter: Exit Behaviour
FP_FOLLOWSPLINE_OBJECT_EXITBEHAVIOURParameter: Target Group
FP_FOLLOWSPLINE_OBJECT_TARGET_GROUPParameter: Create Group
FP_FOLLOWSPLINE_OBJECT_CREATEGROUP