Appointments + , optional fields

Hi! Is there a way to add some optional fields to the appointment scheduling page that will also be shown in the appointments back-end admin view.

I know I could add a form field easily to the appointments page, but then that data would be elsewhere in the admin view.

I would like the data to be with the appointments data when you look at the appointments, so what are some pointers you can give me on the easiest way to edit the php files to to two fields:

The two fields I want are: A comment box. (opt), and a checkbox (are you dropping off the vehicle or will you be waiting to pick it up, also optional field).

Hope that makes sense, thanks!!