You can set the Referer in the HTTP::Request object:

use HTTP::Request;
use LWP::UserAgent;
                                                                      
+          
my $agent = LWP::UserAgent->new();
                                                                      
+          
my $req = HTTP::Request->new(GET => 'http://localhost' );
                                                                      
+          
$req->referer('http://localhost/');
                                                                      
+          
my $response = $agent->request($req);
[download]

/J\