Changing the target thank you page based on field data

I have a template form for signing up to watch our webinars. Based on the webinar chosen, I send people to the specific page with the webinar on it.

So that I dont have to create a bunch of duplicate forms for every webinar, is it possible to make the Confirmation Page URL that the form sends the visitor to different based on which webinar they registered for?

Thanks. Wish this was managed via a plugin, but anyway, this explains how to redirect, but what I want to send them to a page on the same site. I realize "Redirect" can do that, but is "Page" also valid to use?