Reverse concatination-function possible?

 hi,

I have successfully written concatination function like this:

SQL> SELECT agg_concat_count(text) FROM (
  2  SELECT 'z' AS text FROM dual
  3  UNION ALL
  4  SELECT 'z' AS text FROM dual
  5  UNION ALL
  6  SELECT 'b' AS text FROM dual
  7  UNION ALL
  8  SELECT 'c' AS text FROM dual
  9  UNION ALL
 10  SELECT 'd' AS text FROM dual
 11  UNION ALL
 12  SELECT 'e' AS text FROM dual
 13  UNION ALL
 14  SELECT 'e' AS text FROM dual
 15  UNION ALL
 16  SELECT 'e' AS text FROM dual
 17  UNION ALL
 18  SELECT 'e' AS text FROM dual
 19  );

AGG_CONCAT_COUNT(TEXT)
-----------------------------------------------
2|z|1|b|1|c|1|d|4|e|

But I need also a function with the reverse functionality. Like this