What weight loss supplement or powder can help me trim my belly a little?

I like my body but some fat has gone to my belly, nothing severe. I want to control it or do what I can without losing everything else, or losing to much weight. I believe in diet and exercise but I am pretty sure they have supplements specialized for belly fat. I need something I can get at gnc, cvs, or walmart. Also, does green T mega tea work? I think its in pill form.