redirecting with POST data

I need to create a form with an action that redirects the user to a 3rd party site with the POST method.

Gravity looks like it'll do pretty much anything. But I'm querying this because in the support documentation it describes the confirmation redirect setting as sending a querystring:

'The redirect is an advanced form confirmation that allows you to redirect the user to any URL after the form has been submitted. This option also gives you the ability to pass form field data to the redirect page via query string parameters. Using the built in query string builder you can pass form field data to the page you are redirecting to.'
from the bottom of this page: http://www.gravityhelp.com/documentation/page/Form_Settings

Can it use POST instead?

Hi David,
I have the same need as clairee.
I want to use data entered into a gravity form to send parameters to a payment gateway.
Does it mean that if I want to redirect to a specific page, with POST parameters, I have to do it programaticaly and not configure any Gravity redirection?