Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Start Frame
ABCEXPORT_FRAME_STARTParameter: End Frame
ABCEXPORT_FRAME_ENDParameter: Frame Step
ABCEXPORT_FRAME_STEPParameter: Subframes
ABCEXPORT_SUBFRAMESParameter: Selection Only
ABCEXPORT_SELECTION_ONLYParameter: Global Coordinates
ABCEXPORT_GLOBAL_MATRIXParameter: Cameras
ABCEXPORT_CAMERASParameter: Subdivision Surface
ABCEXPORT_HYPERNURBSParameter: Splines (Curves)
ABCEXPORT_SPLINESParameter: Subdivision Surface Weights
ABCEXPORT_SDS_WEIGHTSParameter: Hair (Curves)
ABCEXPORT_HAIRParameter: Particles
ABCEXPORT_PARTICLESParameter: XRefs
ABCEXPORT_XREFSParameter: Particles (Geometry)
ABCEXPORT_PARTICLE_GEOMETRYParameter: Visibility
ABCEXPORT_VISIBILITYParameter: Normals
ABCEXPORT_NORMALSParameter: UVs
ABCEXPORT_UVSParameter: Polygon Selections
ABCEXPORT_POLYGONSELECTIONSParameter: Vertex Maps
ABCEXPORT_VERTEX_MAPSParameter: Vertex Colors
ABCEXPORT_VERTEX_COLORSParameter: Points Only (Geometry)
ABCEXPORT_POINTS_ONLYParameter: Display Colors to Vertex Colors
ABCEXPORT_DISPLAY_COLORSParameter: Merge Generated
ABCEXPORT_MERGE_CACHE