Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Objects
ID_ST_OBJECT_OBJECTS
Parameter: Hidden
ID_ST_OBJECT_LINE_HIDDEN
Parameter: Visible
ID_ST_OBJECT_LINE_VISIBLE
Parameter: Type
ID_ST_OBJECT_SPLINE_TYPE
Parameter: Intermediate Points
ID_ST_OBJECT_SPLINE_INTERPOLATION
Parameter: Number
ID_ST_OBJECT_SPLINE_SUBD
Parameter: Angle
ID_ST_OBJECT_SPLINE_ANGLE
Parameter: Maximum Length
ID_ST_OBJECT_SPLINE_LENGTH
Parameter: Mode
ID_ST_OBJECT_LINES_MODE
Parameter: Lines
ID_ST_OBJECT_LINES
Parameter: Border
ID_ST_OBJECT_BORDER
Parameter: Edges
ID_ST_OBJECT_EDGES
Parameter: Contour UVW
ID_ST_OBJECT_UVW