Import stock updates into Magento 1.5

We are looking for a PHP script that will update stock levels in Magento by directly writing updates to the MySQL database. The information is provides as a CVS file (two columns – SKU and stock level) sitting on a local file system. The script iterates through the Magento product table using the SKU (the SKU in the Magento is prefixed - so the prefix needs to be stripped of; only two letters) to look up stock values in the provided CVS file and updates Magento with this value. If the value is Zero that that product has to be set to “out of stock” in the database as well and if the value is greater than Zero it needs to be verified that the product is set to “in stock”. If a Magento product (SKU) is not in the provide CVS file an Email should be send with that SKU.