Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Curve
BASEGROUP_SUBFACTOR_CURVE_SLIDERParameter: Surface U
BASEGROUP_SUBFACTOR_SURFACE_U_SLIDERParameter: Surface V
BASEGROUP_SUBFACTOR_SURFACE_V_SLIDERParameter: Apply
BASEGROUP_SUBFACTOR_BUTTONParameter: Type
BASEGROUP_SELECT_TYPEParameter: Subtype
BASEGROUP_SELECT_SUBTYPEParameter: Deselect
BASEGROUP_DESELECT_BUTTONParameter: Select Additionally
BASEGROUP_SELECT_BUTTONParameter: Select Only
BASEGROUP_SELECTONLY_BUTTONParameter: Convert to Polygons
BASEGROUP_CONVERT_TOPOLYSParameter: Convert to Arranged Polygons
BASEGROUP_CONVERT_TOGROUPSParameter: Convert to one Object
BASEGROUP_CONVERT_TOONE