Thanks for the suggestions but i don’t think these will give me what I need.
If I understand these solutions suggestions correctly, they would change the format for all of my ticket emails, not just the ones that need to send the secret address. I need something that will allow me to select which events need special information added to the Ticket Email.
So far my best solution is to use the header image upload. I will go to the Suggest a Feature forum and request that in addition to being able to upload a Header Image for each ticket email we get the ability to upload a text block to be displayed just below the Header image.