How can I add an autoresponder to Xara Designer?

I would alos lie to know how to add a student registration form to Xara Designer Pro

You need to first create your form with Jotform, https://www.jotform.com/help/2-How-to-Create-Your-First-Web-Form.

Once the form is created, you can embed it to Xara Designer. You have a few choices in the Publish wizard;

https://www.jotform.com/help/67-Which-Form-Embed-Code-Should-I-Use