Well, you can but your going to kill off the chick that is developing in the original eggs. Try setting some fake plastic, wooden or golfballs under her. I know when they are dead set on sitting on air that they will continue on for another 21 days til something hatches.
Welll if you get a hen to go broody, you can put golf balls or fake eggs underneath her instead of using real eggs. She won't know the difference. Then you could take them out and put your boughten eggs underneath, and she should sit on them for the next 21 days.