Basic usage
You have to place on map a chest... Oops, sorry, ANYTHING! Then, set for it an actionid 2000 and uniqueid you wish, but watch out- it will be used as storage for player!
Now, if the item is not a container, just save your map and run on server- reward will be a clone of the item you've used.
If not, then put to the container item(s) you wish to be as reward(s).
Follow the save and run part, and poff, you've just designed a quest!