Iphone App

We need an application for IPhone that will interact with our ecommerce system. The application should present recent customer Orders with detailed view of each order when the order is clicked. the user should have an initial config screen where he enters his website url ,user name and password so the system will identify him. All data will be loaded from our website. You should tell us how would you like to receive the data to the Iphone Application , our application works on C# and XML.