Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Friction
FRIC_FRIC
Parameter: Spin Friction
FRIC_SPINFRIC
Parameter: Mass Dependence
FRIC_MASSDEP
Parameter: Size Dependence
FRIC_SIZEDEP
Parameter: On
IN_FRIC_ON
Parameter: Animation Time
IN_FRIC_ATIME