If you're trying to just get the data, while passing the authentication to the Basic Authentication you've got set up, you can do it in the following fashion (using LWP):

    use strict; 
    use LWP::UserAgent;

    my $url      = 'https://intranet.com/some/page.html';
    my $browser  = LWP::UserAgent->new();
    $browser->protocols_allowed(["http", "https"]);

    unless ($browser->is_protocol_supported("https")) {
            die "Cannot use https:// URLs\n";
    }

    $browser->credentials("intranet.com:443", "My Realm",
                          "johndoe", "0bScUr3d");

    my $response = $browser->get($url);
[download]

Work with this code snippet, and get something similar working in your CGI.. you should have no trouble from there.