Creating \"Backorder\" in opencart.

I already have an opencart website, but My client needs to have a new page. I believe it is a function. It's called "backorder" Do visit [login to view URL] - there is a menu section called BACKORDER In the section there are: - current-backorders (extra items for sale from people who ordered) - Extras From Backorders (extra items for sale from people who ordered) - Archives (All sold out items' history) - Backorder Status (A manual text input page)