not an ideal solution and no doubt someone will come back with a clever code to do what you want but heres a simple solution.
If you look at your site and view a product in the IE address bar you will see something like
once you know the format it's easy to just put a link on the page where you want it to show.
The when you want to change it add the product normally, view it is IE look at the address and change the ProductID= from 5 to say 23
I've tried it and for a non php coding solution it does as they say "work for me"