Custom Order Numbers For Magento Stores

I have multiple Magento storefronts, and previously, they were all running on a different order number series. I'd like to keep the order number series separated by store. I have looked into another extension that you can install, but it isn't working. This project will require you to look into all of the tables and see how Magento handles order numbers, figure out how to adjust all of the order numbers per store, and then create an easy to use interface so I can adjust it myself.