This is in response to a topic I saw earlier, but can't find anymore.
When the need to do this arrises, I would caution against using the Acrobat Document object's submitForm method to do it. It may work, but it may cause a lot of problems as that method is designed to work with Acroforms. You can change the URL of a submit using JavaScript similar to the following:
var blah = this.resolveNode("#event.submit");
blah.setAttribute("http://www.google.ca", "target");
Chris
Adobe Enterprise Developer Support