If you supply too many arguments to SYSCS_UTIL.SYSCS_EXPORT_QUERY_LOBS_TO_EXTFILE, you get an error message telling you that SYSCS_UTIL.SYSCS_EXPORT_QUERY_LOBS_TO_EXTFILE is an unknown procedure. Instead, you should get an error message which tells you that the signature can't be matched to a known overload of the procedure:
ij> call SYSCS_UTIL.SYSCS_EXPORT_QUERY_LOBS_TO_EXTFILE
'select * from lobtable where updateCount in( 2, 4 )',
ERROR 42Y03: 'SYSCS_UTIL.SYSCS_EXPORT_QUERY_LOBS_TO_EXTFILE' is not recognized as a function or procedure.