Amazon Posting Listing without ASIN.

I need to be able to post a new products to Amazon to sell them and they are not yet on Amazon's catalog, have no ASIN. I know there is a way to do this since companies like ChannelAdvisor and ChannelSale offer this as a service, so it is doable. As a proof of concept, I want to post a variation garment item like this one: B00OO4TPXQ with various sizes. From what I know MWS has a different XSD for each category, so we should be able to post for various categories. code should be in vb.net compatible with VS 2010