Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See page_maxonapi_getting_started_foundations_cinema_parameters.
Parameter: Surface Type
BASESURFACE_TYPE
Parameter: Make NURBS
BASESURFACE_MAKENURBS
Parameter: Output
BASESURFACE_OUTPUT
Parameter: Subdivisions U
BASESURFACE_USUB
Parameter: Subdivisions V
BASESURFACE_VSUB
Parameter: Calculate Normals
BASESURFACE_NORMALS
Parameter: Swap Normals
BASESURFACE_SWAPNORMALS
Parameter: Enable
BASESURFACE_TESTON
Parameter: Position U
BASESURFACE_TESTUPOINT
Parameter: Position V
BASESURFACE_TESTVPOINT