use HTTP::Cookies ();
use SOAP::Lite ();

## ...snip...

## create a cookie for authentication
my $cookie_jar= HTTP::Cookies->new;
$cookie_jar->set_cookie(
	0,               # cookie version
	key => 'value',  # key and value
	'/',             # path
	$host,           # domain
	$port,           # port
);

## create the request object
my $request= SOAP::Lite
	->uri($urn)
	->proxy( 
		"http://${host}:$port", 
		cookie_jar => $cookie_jar,
	);


## perform the request
my $response= my_action( $request );

## ...and check for failure
die 'failure! ', $response->faultstring 
	if $response->fault;