Fixed headers padding at top

Hi

I'm trying to use fixed headers with the twitter bootstrap fix nav bar.

With fixed headers in it's default state when you scroll the header afixes to the absolute top of the browser. This means that it scrolls beneath the nav bar.

So I need a way to force the table header not to be as the absolute top of the page but stop at 60 px below it.

I've tried various CSS methods but can't get this to work, any one have a solution to this?