How To Create & Save Email Template In HTML

How To Create & Save Email Template In HTML

I have designed a newsletter in html and I want to save it as a template in zoho campaigns so that I can quickly create new newsletters.

I know that I can save templates to my library if I edit one of the pre made templates,   is there an edit/view html button in the design from template option so that I could simply copy my html over this and then save? Or  is there a way to do this in the html editor instead? 

Any Ideas?