Delivery Module for OSCommerce - By Distance

Hi all, I need a delivery module making for my OSCommerce Store (v 2.3) The module needs to use Google Maps ideally or another UK route planner to calculate the distance between our shop at 1 postcode and the customers delivery postcode. For example from LS16 8BQ to BD20 0AR returns 17.7 miles as the shortest distance from Google Maps. This would be rounded up to 18 miles and charged per mile at a rate set in the admin for example £1.00 / mile - customer is charged £18 for delivery. The "from" postcode will always remain the same (our shop). I needs this ASAP Thanks