Ability to have a page specific notification panel

I often write processes into confluence. Over time these instructions get replaced. Mostly I just delete the old document when this happens, but sometimes we need to keep two versions alive for a period of time.

I currently notify users of this scenario using a 'warning' macro.

What I would like is a macro that floats a notification directing the user to the new instructions. I'd like this to stick to the top of the page so it is visible no matter how far down the reader scrolls.

I can do this on a self hosted instance using a user macro and CSS, but I can't do this in the Cloud instance of Confluence.