Track supplies inventory -- 2

I have online store, The problem is that the inventory doesn't sync between our store and the supplier. We have an option to export our products with SKU to csv file and then go and search for each SKU separately on the suppliers website and see if it says in stock or out of stock. This is something that needs to be done regularly so it is a pain in the butt when you have hundreds of products to go through. What is my first step to automating this?
My supplier website www.lcwaikiki.com