User Authentication - Portal Error Messages

Hi, We are implementing Portal 6.0 SP12. Portal is connected on the backend with CRM 4.0 and we are connecting Portal to LDAP in order to facilitate SSO, users are pulled out from LDAP, they are not created on Portal.

Passwords on LDAP expires every 30.

If a user gets lock for any reason on Portal he receives a message saying "Authentication Failed", if the user enters a wrong password, he receives the same message, and if his password was expired by LDAP he receives the same message. Is there any way to customize this message in order to display something like "User Lock, contact your system admin" or "Password Invalid"

In advance, thanks for any help on this