Muscle burns fat, that's simple, it's also why just about every guy on Earth bulks first and cuts after.
It's also one of the main reasons you should separate your building and cutting phases, basically, if you attempt to combine them you're asking your body to do two almost opposite things at once. You can do it, but it takes one hell of a workout, one hell of a diet and one hell of a comittment. Most average working guys just don't have the resources needed.
You really can't target fat loss; but you can push it around at will. If you're pretty much OK with the rest of your body (or it's progress) then you can hit those lower abs like this:
1. Plastic wrap, just like you'd wrap leftovers with
2. Preparation H, Yep "The 'Roid Creme"
3. Neoprene sweat belt, about 10-15 bucks at any sporting goods store.
Before bed rub the ol' roid creme onto yer belly, Saran wrap that shit two or three times around then cinch that neoprene belt nice and snug. Not too tight, you still wanna breathe; should feel like a willing pussy all 'round yer middle.
Try that for about two weeks and let us know how ya feel.
Guys in the srevice have used this to make bodyfat measurements for years.
Now, don't neglect any of your other workout components; this is an adjunct, not a replacement.