Creating a customized form to add to an automated request an update workflow

I want to create a workflow where on a weekly basis I request an update from those assigned to a task, and they can respond using a form. This form would only allow them to respond in two of the fields ("% Complete" and "Latest Updates"). How do I create a form where I hide or disable the ability to complete all the other fields as populated from the Columns in my sheet (but maintain visibility if possible), and then how do I add the form into the workflow to request an update.