Unfortunately, you can't 'spot reduce' - i.e., short of liposuction, you can't MAKE your body lose fat in specific areas. Fat is systemic - when your body burns fat, it'll take it from the most convenient/easiest place on your body. In my experience, it's a matter of 'last on - first off' as far as taking fat off goes.
We all have different 'stubborn spots' - for me it was my thighs...
What you need to do (if you're not doing so already) is reduce your calorie intake and bring your cardio up. Weight training helps tremendously too - but if you don't make nutrition changes and add cardiovascular exercise, you will end up with muscles covered with a thick layer of fat!
You might want to check out the Ladies Who Lift (LWL) forum for some upper-back exercises - get into what we at LWL call the LWL Trinity (Nutrition, Cardio, Weight Training) and you'll lose weight AND look great this coming year