Get your taxes done using TurboTax

I am working on NY state Taxes, but if you right click on the box that shows the amount you want refunded or rolled over to next year, and go to the Data Source, it should bring you to a Tax Payment or Estimated Tax Worksheet where you can edit the amount.
And no, you cannot use your State Refund for Federal or visa-versa.  I always just roll it over for next year and use any refund for my first Quarter Estimated Taxes.  It helps keep the Tax Penalties Monster away.