Actually your outside scholarships probably will not reduce the amount of money that your parents will have to pay.
[quote=UNC]
How will my financial aid be adjusted for the reporting of an outside scholarship
Due to regulations, we must adjust need-based aid to account for the reporting of outside scholarships. We always reduce need-based loans or work-study before reducing any gift aid, like need-based scholarships or grants.
https://studentaid.unc.edu/current/what-aid-is-available/outside-scholarships/[/quote]
You would have to get enough money in outside scholarships to cover all of your financial aid before the amount of money that your parents have to pay decreases.