Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See page_maxonapi_getting_started_foundations_cinema_parameters.
Parameter: Weight Tag
FIELDLAYERMOGRAPH_LINK
Parameter: Mode
FIELDLAYERMOGRAPH_MODE
Parameter: Radius
FIELDLAYERMOGRAPH_RADIUS
Parameter: Distance Falloff
FIELDLAYERMOGRAPH_DISTANCEFALLOFF
Parameter: Constant Update
FIELDLAYERMOGRAPH_CONSTANTUPDATE
Parameter: MoData Sub-Index
FIELDLAYERMOGRAPH_SUBINDEX