calculate the shipping range based on the total products excluding taxes Without considering the cost of shipping?

[TeamBit]

Hello,
I would need to modify the data used in some way to vary the shipping expense range. At the moment I noticed that the tax included subtotal is used, I would need that the shipping price ranges vary according to the tax excluded subtotal. I'm talking about the checkout page.
Does anyone know how and where to put their hand?
Thank you

I rephrase the question:
On the cart page, Is it possible to calculate the shipping range based on the total products excluding taxes Without considering the cost of shipping?
At the moment, it uses the total amount of the purchase, including taxes, but there is also the cost of shipping in there, which shouldn't be logically.