Hide a Post but have a Link to it in Sidebar

I want to hide a Post so it does not show up in my posts or blog. But I want a link to it in the sidebar.
If I make it private, the link doesn't work. Yes I can do this with a page (hide the page in Atahualpa options), but it needs to be a Post, not a Page. How do I do this? I don't see an option to hide a Post in Atahualpa.

Thanks