What do you mean by a file path that is password protected? Do you want to save to a folder that requires a password to open? You'd have to open that folder manually and specify the password first.
Do you want to protect the PDF so that a password is required to open it? I think you can do that if you specify the correct options but you won't be able to use a field in the database to specify the password. Every copy produced by such a script would be protected with the same password.