[Zope] Passing a Variable from PHP

Hi; I need to pass a variable from a php script (served by Apache) to a Zope script (served by ZServer). I can't do this as a hidden field in a form since there is no *form* on the php script: indeed, the user never notices the script as it doesn't generate any html. This is a randomly generated variable. How do I communicate it? TIA, BenO