We want a button-link in our Orbeon form that opens a screen (we navigate
from our form to that screen, and from that you can return to the form).
The link that will open that button-link, comes from an external
application. How can we store that link in our form, so that when we click
on the button, we collect that external information that arrives to us, and
go to the corresponding screen? We don't want to save that information from
the link that we must open from the button, in a hidden field of the form.