soap::lite wsdl client - how to set header?

Newbie SOAP:Lite question, so apologies in advance!

I have a client initialized with a wsdl file as follows:

use SOAP::Lite;
my $service = SOAP::Lite->service('file:///.../stockquote.wsdl');
print $service->GetPrice('aCompany','25-Dec-03'), "\n";

This works fine and results in a SOAP message with a body but no header.
What I'd like to do is specify one or more header blocks as well. It looks
like I need something like:

SOAP::Serializer->envelope(SOAP::Header->name(t1 => 5)->mustUnderstand(1),);

Is this the correct approach and how would I combine this with my program?

Many Thanks
Rob Henley