umm... good luck getting any employees to voluntarily contribute. Why would they put in money that they themselves might not get back if they aren't the one to help you out? I've never played the lottery because it is a tax on fools. Your setup would be the same.
If you want to motivate employees, there are much better ways to do so! No one is going to go above and beyond at the chance of a $5-500 payout.
http://open.lib.umn.edu/organization...ce-incentives/
I'd suggest seeing a local attorney about your scheme, but it's probably not worth the $s you would pay to have him/her laugh at the idea.

