Oracle Spatial (SDO_GEOMETRY) using procedure to load data dynamically with LISTAGG function.

Inexperienced at using Oracle Spatial (SDO_GEOMETRY) and trying to use a procedure to load data latitude/longitude from a table dynamically using a LISTAGG function.  

Keep getting an error "ORA-01722: invalid number" that I believe has to do with the LISTAGG (v_lat_long_list) variable. Using the debugger I can 'see' the same list of numbers that I was able to load without the variable below.  Is there another way to load this SDO_GEOMETRY function dynamically?



CREATE OR REPLACE procedure test_insert
IS
  v_lat_long_list   VARCHAR2(32767);

BEGIN
 
select LISTAGG(GEOPOSITION_LONG|| ',' || GEOPOSITION_LAT || ',') WITHIN GROUP (ORDER BY GEOPOSITION_LONG)
 into v_lat_long_list
 from SECTOR_LAT_LONG
 where sector_mod = '5710M1';
 
 v_lat_long_list := rtrim(v_lat_long_list,','); -- to remove ending comma
 
    INSERT INTO cola_markets_lat_long VALUES(
    '5710M1',
    SDO_GEOMETRY(
    2003,
    NULL,
    NULL,
    SDO_ELEM_INFO_ARRAY(1,1003,1),
    SDO_ORDINATE_ARRAY(v_lat_long_list)
    )
    );
 
commit;

END;

---------------

INSERT INTO cola_markets_lat_long VALUES(
    '5710M1',
    SDO_GEOMETRY(
    2003,
    NULL,
    NULL,
    SDO_ELEM_INFO_ARRAY(1,1003,1),
    SDO_ORDINATE_ARRAY(
-120.02, 51.24,
-120.25, 51.19,
-120.25, 51.99,
-120.04, 51.93,
-120.95, 50.87,
-120.84, 50.92)
)
    );