Yes, you should be able to do that with LWP::UserAgent, or her prettier daughter WWW::Mechanize. Supersearch or google around for people using these modules to fill out forms.

However, especially if you are on a windows box, beware that with https you will require the amulets Crypt::SSLEay and an Openssl installation to slay the strange errors you are likely to get when accessing https urls. (But not http urls.)

You can supersearch around for that too.

Good luck.