How to split comma separated string and pass to IN clause of select statement/ Create Comma Separated String using Select statement

SELECT   COLUMN_NAME
       , COLUMN_ID
    FROM DBA_TAB_COLUMNS
   WHERE TABLE_NAME = :P_TABLE_NAME
     AND OWNER = :P_OWNER
     AND COLUMN_NAME NOT IN (SELECT REGEXP_SUBSTR (:L_STRING
                                                     , '[^,]+'
                                                     , 1
                                                     , LEVEL
                                                      )
                                   FROM DUAL
                             CONNECT BY REGEXP_SUBSTR (:L_STRING
                                                     , '[^,]+'
                                                     , 1
                                                     , LEVEL
                                                      ) IS NOT NULL)
ORDER BY COLUMN_ID ASC

WHERE AS THE l_STRING CAN BE PASSED AS 'COLUMN1,COLUMN2,COLUMN3'

Use Below SQL to create comma separated string for multiple rows.
Limitations : The below SQL has String length Constraint. If the length of number of rows in a column getting converted into one row searating each other by using any separator, in that case the length should not exceed 2000 characters. 

SELECT SUBSTR(SYS_CONNECT_BY_PATH(''''||lookup_code||''''
                                    , ',')
                , 2)
              lookup_code
      FROM (SELECT lookup_code
                 , ROW_NUMBER() OVER (ORDER BY lookup_code) rownumber
                 , COUNT( *) OVER () cunt
              FROM fnd_lookup_values
             WHERE lookup_type = 'ITEM_TYPE'
               )
     WHERE rownumber = cunt
START WITH rownumber = 1

CONNECT BY rownumber = PRIOR rownumber + 1