VBA code to Get/Set Stock Levels in my Amazon Store, using Amazon API

I have developed a basic Product Inventory database, using Microsoft Access 2007, for my small business.

I need to be able to programmatically adjust stock levels, one product at a time, in my Amazon on-line store.

My initial thoughts are that I will need a new VBA Class enabling me to (a) securely connect to the on-line Amazon store,(b) Get and Set stock levels for a given product and (c) disconnect. The product would be identified by its SKU or ASIN number. Suitable success/failure confirmation would be needed, along with any error/warning messages returned from Amazon. The Class should make use of the Amazon Marketplace Web Service.

It is envisaged that in due course the Class will be extended to perform more complex tasks, but for now all that is required is as described above.

If it is not possible to create the code entirely in VBA, then a VB.NET or C#.NET component is acceptable, provided that the solution is usable from within MS Access VBA and that detailed instructions are given to achieve this.

Start: A.S.A.P.
Deadline: End October 2013
Deliverables: (a) Well commented source code, (b) installation instructions, (c) VBA example of usage.

I'm comfortable with VBA and basic VB.NET but have no experience connecting to Amazon programmatically.