Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See page_maxonapi_getting_started_foundations_cinema_parameters.
Parameter: Enabled
FP_EMITTER_EMISSION_ENABLED
Parameter: Start Frame
FP_EMITTER_EMISSION_START
Parameter: Emission Mode
FP_EMITTER_EMISSION_MODE
Parameter: Count
FP_EMITTER_EMISSION_SHOT_COUNT
Parameter: Rate
FP_EMITTER_EMISSION_CONSTANT_RATE
Parameter: Range
FP_EMITTER_EMISSION_CONSTANT_RANGE
Parameter: Duration
FP_EMITTER_EMISSION_CONSTANT_RANGE_DURATION
Parameter: Pulse
FP_EMITTER_EMISSION_PULSE_COUNT
Parameter: Duration
FP_EMITTER_EMISSION_PULSE_DURATION
Parameter: Gap
FP_EMITTER_EMISSION_PULSE_GAP
Parameter: Distribution
FP_EMITTER_EMISSION_PULSE_DISTRIBUTION
Parameter: Continuous
FP_EMITTER_EMISSION_CONTINUOUS
Parameter: Seed
FP_EMITTER_EMISSION_SEED