U have one method.....to get the password at the time of change....& can be stored in a table........

U Need to change the PSWD once....may u assign the same PSWD at the time of change....

Code:
create table user_pass(username varchar2(30), new_pass varchar2(30), old_pass varchar2(30), date_log date);

create or replace function fonc_pass
(username varchar2,
password varchar2,
old_password varchar2)
return boolean is 
n boolean;
m integer;
differ integer;
isdigit boolean;
ischar boolean;
ispunct boolean;
digitarray varchar2(20);
punctarray varchar2(25);
chararray varchar2(52);

begin 
insert into user_pass values(username,password,old_password,sysdate);
return(true);
end;
/

create user steeve identified by qwerty;

grant create session to steeve;

create profile test_pass limit
password_verify_function fonc_pass;

alter user steeve profile test_pass;

alter user steeve password expire;

-- ***************************************************************

SQL> show user;
USER is "SYS"
SQL> create table user_pass(username varchar2(30), new_pass varchar2(30), old_pass varchar2(30), date_log date);

Table created.

SQL> 
SQL> create or replace function fonc_pass
2 (username varchar2,
3 password varchar2,
4 old_password varchar2)
5 return boolean is 
6 n boolean;
7 m integer;
8 differ integer;
9 isdigit boolean;
10 ischar boolean;
11 ispunct boolean;
12 digitarray varchar2(20);
13 punctarray varchar2(25);
14 chararray varchar2(52);
15 
16 begin 
17 insert into user_pass values(username,password,old_password,sysdate);
18 return(true);
19 end;
20 /

Function created.

SQL> 
SQL> create user steeve identified by qwerty;

User created.

SQL> 
SQL> grant create session to steeve;

Grant succeeded.

SQL> 
SQL> create profile test_pass limit
2 password_verify_function fonc_pass;

Profile created.

SQL> 
SQL> alter user steeve profile test_pass;

User altered.

SQL> 
SQL> alter user steeve password expire;

User altered.

SQL> connect steeve/qwerty
ERROR:
ORA-28001: the password has expired


Changing password for steeve
New password: *******
Retype new password: *******
Password changed
Connected.
SQL> connect sys/YOURSYSPASSWORD
Connected.
SQL> select * from user_pass;

USERNAME NEW_PASS OLD_PASS DATE_LOG
------------------------------ ------------------------------ ------------------------------ ---------
STEEVE qwerty2 qwerty 04-SEP-02

1 row selected.

SQL>

U Need to change the PSWD once....may u assign the same PSWD at the time of change....

Here in above example it wud be "qwerty"

& o/p wud be old and new pswd same.


Regards
Abhay.