Keep Subheaders Visible At Top Of Screen?

Been trying to figure out if there's a way to keep sub-headers visible at the top of the screen.

Basically I want the main headers locked at the top (via freeze panes), but then I also want certain rows, which would be sub-headings, to stick to the top of the screen until the next sub-header row gets to the top of the screen, at which point that row would replace the other one at the top.

The best example I can provide of the behavior I'm looking for is on the iPhone Contacts list. When you scroll through the contacts you see the listings, but as you scroll into each new letter that particular letter's sub-heading stays stuck at the top of the screen until you scroll down to the next letter.

So example would be:
Quantity Item Price (this would be the header row locked to the top via freeze panes)
PRODUCE
1 Apple $1
6 Orange $1
8 Pear $2
DAIRY
1 Cheese $5
7 Milk $2

So if you scrolled the above list down PRODUCE would stay at the top even while the Apple, Orange, and Pear lines scrolled off the screen, then it would get replaced with DAIRY when DAIRY reached the top of the screen.