Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Isoparm Subdivision
SWEEPOBJECT_ISOPARM
Parameter: End Scale
SWEEPOBJECT_SCALE
Parameter: End Rotation
SWEEPOBJECT_ROTATE
Parameter: Start Growth
SWEEPOBJECT_STARTGROWTH
Parameter: End Growth
SWEEPOBJECT_GROWTH
Parameter: Parallel Movement
SWEEPOBJECT_PARALLEL
Parameter: Constant Cross Section
SWEEPOBJECT_CONSTANT
Parameter: Banking
SWEEPOBJECT_BANKING
Parameter: Keep Segments
SWEEPOBJECT_KEEPSEGMENTS
Parameter: Use Rail Direction
SWEEPOBJECT_RAILDIRECTION
Parameter: 2-Rail
SWEEPOBJECT_BIRAIL
Parameter: Use Rail Scale
SWEEPOBJECT_RAILSCALE
Parameter: Flip Normals
SWEEPOBJECT_FLIPNORMALS
Parameter: Stick UVs
SWEEPOBJECT_GROWUV
Parameter: Scale
SWEEPOBJECT_SPLINESCALE
Parameter: Rotation
SWEEPOBJECT_SPLINEROTATION
Parameter: Rotation from
SWEEPOBJECT_ROTATIONFROM
Parameter: Rotation to
SWEEPOBJECT_ROTATIONTO