Welcome message on Desk login page

Welcome message on Desk login page

I would like to have the ability to add a welcome message to our Zoho Desk customer facing login page. 

The message would include hours and phone, and a note on how to create an account. It may also have a warning message for unauthorized users. It should support up to 800 characters and minimal HTML (<a href>, <b>, <br>, <p>).

 If a welcome message is entered, just insert it over the forgotten password / agent login links. If no welcome message is entered, the page will display as it currently does.

I have attached an example mockup of what this might look like.