Magento

Hi

I want to know which is the file where the shipping price is added to the grand total, no matter of what shipping method i choose.
I want to show the shipping price, but don’t want it added to the grand total

for example if I have a Subtotal = $100, Shipping & Handling = $10, I want the Grand total to be $100 and not $110.

PS: maybe you could tell me where should i look up to change the subtotal to be the subtotal - tax

Thanks

Please...anybody?