Hi, You can't do that with LWP::Simple. See http://search.cpan.org/~gaas/libwww-perl-5.805/lwptut.pod#HTTP_Authentication for a tutorial.

use strict;
use LWP;
my $browser = LWP::UserAgent->new;
  
$browser->credentials(
      'www.mydomain.com:80',
       # Look up this realm with your browser, eg. Firefox
      'web_server_usage_reports', 
      'user_plinky' => 'Password_banjo123'
);

my $url =
  'http://www.mydomain.com/program.cgi?var1=apples&var2=bananas';
 
my $response = $browser->get($url);

#......
[download]

Hope this helps