Hi Ashwin,
CR does not store passwords, so you'd need to get in touch with the maintainer of the app these reports are run in.
You'd need to save the database password and only the app maintainer could tell you how.
Another option is to use the 'Integrated Security' option. This essentially logs onto the database using your Windows credentials, however, the database needs to be configured for this type of log-in as well.
-Abhilash