hmmm maybe some crazy contraption of a few suction cups and some bridal veil?
I've noticed that once you peel the zoo, it takes about 2-3 days before they'll be willing to attach. So just keep it in your tank in a flow flow section in a cup for a day or two, then try to attach it. It'll attach quickly then.
The other possibility would be to let it attach to a small rock, and just glue the rock to the glass with putty?