Shipping Script in Php / dotnet

can u write script in dotnet which work good with php code , I have site developed for my client in Magento . Its based on Php, Client is distributor of [login to view URL] selling their products my php code will pass on product id ( same as papermart items number) along with product qty , shipping address of customer now your script will cauculate shipping cost , shipping option to my php code got my concept ? Your script objective is to calculate shipping option , cost for our items. We need to to fetch shipping cost from [login to view URL] for any product added into cart with qty.