I semi answered this in the PM you sent me.
When an item is added to the cart, Magento creates a “Quote” object which contains info about the product. Once the person checks out, the Quote items is converted to a “Sale” item.
The best way to do what you want is slightly more complicated than you are thinking.
1) Create a custom module. This will allow you to do a few things.
2) Use Events described in the stickied post in this forum topic.
3) Your custom module will probably use a standard connection, but you’ll need to find some code example with dealing with custom data-table calls. I’m not sure about that off the top of my head.
See the thread I sent you in the PM. This one: http://www.magentocommerce.com/boards/viewthread/18081/
Hope that thread helps. I really need to write out everything I did for that…