Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See page_maxonapi_getting_started_foundations_cinema_parameters.
Parameter: Start Position
MDATA_MGLINEARTOOL_START
Parameter: End Position
MDATA_MGLINEARTOOL_END
Parameter: Clones Count
MDATA_MGLINEARTOOL_COUNT
Parameter: Generate
MDATA_MGLINEARTOOL_MODE