WITH t AS
(
SELECT 'A' col1, 'AABB' col2, '' col3 FROM dual
UNION ALL SELECT 'A1', 'CCDD', ''     FROM dual
UNION ALL SELECT 'Z' , ''    , '1212' FROM dual
UNION ALL SELECT 'Z1', ''    , '3434' FROM dual
)
SELECT SUBSTR(c1,  1, 1) col1
     , SUBSTR(c2, lv, 1) ||
       SUBSTR(c3, lv, 1) col2
  FROM (SELECT REPLACE(col1, 'Z', 'A') c1
             , MIN(col2) c2
             , MIN(col3) c3
          FROM t
         GROUP BY REPLACE(col1, 'Z', 'A')
        )
     , (SELECT LEVEL lv FROM dual CONNECT BY LEVEL <= 9)
 WHERE lv <= LENGTH(c2)
 ORDER BY c1, lv
;

 마농님은 참 대단한것 같아요.

저는 질문을 이해할 수 없었는데...

마농님 댓글 보니 이해가 가네요 ^^