Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Mode
MDATA_LIGHTPLACER_MODEParameter: Selection Method
MDATA_LIGHTPLACER_SELMODEParameter: Modify Lights Only
MDATA_LIGHTPLACER_LIGHTONLYParameter: Highlighting
MDATA_LIGHTPLACER_HIGHLIGHTINGParameter: Quick Interaction
MDATA_LIGHTPLACER_QUICKParameter: Pivot
MDATA_LIGHTPLACER_PIVOTParameter: Place Pivot
MDATA_LIGHTPLACER_PLACEPIVOTParameter: Add Light
MDATA_LIGHTPLACER_ADDLIGHT