Possible to Pass Data from Market Form to External App

Let's try this. I feel like it must be able to do this, but I cannot find documentation and I have searched through every option in Market and can't figure it out.

Basic question: Can I tokenize fields to pass as part of a redirect after a Contact or Lead submits a form?

In a Form I have fields and they are mostly associated with SugarCRM fields. For example, first_name, last_name, Email, etc.

I want to pass those to an external application.

I can do that via a redirect, but have to tokenize the field names to put in the URL. For example: event.on24.com/.../index.html&firstname=John&lastname=Smith&email=john.smith@abc.com&company=ABC

Their field is &firstname= and I want to be able to send them what is in the first_name field in the form.

I looked at Actions after form completion and couldn't find anything that could send data.

I really, really, really want to be able to do webinar registrations from our landing pages, using our forms so any help would sure be appreciated.