Sorry, missed the login form part.
No, WGet will not be able to help you with that because it's programmatic ... somehow, via a session cookie, or a GET parameter, the server will want to verify that you have a valid session, approved via a password login. I don't believe there's any WGet stuff for that ... it'd need to be WPost for that

So this will need to be a PHP (or a language you're comfortable in) effort. Log in, most likely get a cookie for your efforts, then you'll need to send that cookie up with each request so that the server knows you're logged in. You can do that by hand with sockets, you can try my webRequest class here or, probably the best advice, become conversant with cURL which is complicated and probably way more than you need, but would do the job.