What I have done, is let a hen go broody where she wants and then just mark the eggs I want her to have. but then don't give her a crazy number, and write down the hatch date. The problem with that is she could get into fights with other hens over the nest and they could all get broken. (That is...
Moving a hen would be nice, but they like to go broody where THEY want to go broody. If you do move her mover her with dummy eggs until you know for sure it was a good move. In the middle of the night perhaps.