You would need to use server validation to be able to retain the information.
To add server validation, go to insert -> Web Assist -> CSS Form Builder -> Server Validation.
then select each form item, and in the properties inspector click the lightning bolt next to Initial value and select the corresponding item from the validated entries collection.
This is not going to work with third party captcha however.
One way to work around this, is to create a blank page, and add the secure login form to the page.
you can then copy over the code for creating the captcha element, as well as the server validation server behavior, then add server validations for the rest of the form elements on the page.