Если текст сообщения всегда в этом формате, старый добрый SUBSTR
+ INSTR
+ REPLACE
может выполнить эту работу.
SQL> WITH test (col)
2 AS (SELECT '&message' FROM DUAL),
3 pos
4 AS (SELECT col,
5 INSTR (col, ':', 1, 1)
6 colon_1,
7 INSTR (col, ':', 1, 2)
8 colon_2,
9 LENGTH (col) len
10 FROM test),
11 inter
12 AS (SELECT col,
13 trim(SUBSTR (col, colon_1 + 2, colon_2 - 4 - colon_1)) old_pw,
14 TRIM (RTRIM (SUBSTR (col, colon_2 + 1, len - colon_2), '.'))
15 new_pw
16 FROM pos)
17 SELECT REPLACE (REPLACE (col, old_pw, LPAD ('*', LENGTH (old_pw), '*')),
18 new_pw,
19 LPAD ('*', LENGTH (new_pw), '*')) result
20 FROM inter;
Enter value for message: Password changed from: 12345 to: abcdefg.
RESULT
-------------------------------------------
Password changed from: ***** to: *******.
SQL> /
Enter value for message: Password changed from: abxyz44# to: 87ZU_3.
RESULT
----------------------------------------------
Password changed from: ******** to: *******
SQL>