hand feeding probably wont work, just leave some fying insects in with it and leave it alone for a while in a dark sheltered place.
It would seem to be a bit of a legal grey area you are in, however a unlicenced person can legally keep limited numbers/species(including gracefuls) of wild caught frogs but only when obtained from your own property :?
If you told qpws they would probably have to kill it or give it away to be kept by someone else. Just dont let it go what ever you do.