how to redirect to url using http post

Hello,

Within a peoplesoft page a user needs to click a button to redirect to an external 3rd party website.  The external vendor is asking that the redirect be accomplished using an HTTP POST with the appropriate parameters.  I do not understand how to accomplish a redirect action with a HTTP POST.  I think of a POST as passing information and getting a response message back so I do not understand how to do a redirect to the url.    Can anyone point me in the right direction to research?

Any help is greatly appreciated...

Teresa