Wordpress free shipping conditions

Hello, I'm looking to exclude certain products from free shipping calculation in WooCommerce. For example, I want to set free shipping on all orders from 400$. Example: If the Cart subtotal is 400$, and one of the products is a product which I want to exclude from free shipping and costs 20$, then the free shipping should not apply for this order, since the subtotal for the eligible products is 380$. Notice though, If all the eligible products total is 420$ for example, and there is an excluded product in the cart which costs 20$, so the subtotal for the whole cart should be 440$. In that case the cart is VALID for free shipping, due to the fact of enough eligible products exceeding 400$, regardless to the excluded product being part of the purchase. Excluded products can be part of an order but won't have affect on getting free shipping! If you can make this happen for my site I am more then willing to hire you for the project!