Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See page_maxonapi_getting_started_foundations_cinema_parameters.
Parameter: Create Vector Object
AIIMPORTFILTER_CREATE_VECTOROBJECT
Parameter: Force PDF
AIIMPORTFILTER_FORCE_PDF
Parameter: Greedy Fill
AIIMPORTFILTER_GREEDY_FILL