I have created a caluclator which uses the H-B formula for BMR and macronutrient calculations. Click here:
http://www.geocities.com/mwhalber1/Fitness.xls to download it.
If you are trying to lose weight, you might find that you will need to tweak the macronutrient numbers in the spreadsheet a little...i.e. lower fat % to about 10% and recalculate.
The other Macronutrient ratios in the spreadsheet are dependent on your Fat intake percentage and your BMR.
Please let me know if you like the application/spreadsheet!

I hope it helps!
Furthermore, you can check out johnstonefitness.com and forums.johnstonefitness.com
Great stuff...lots of information and very motivating.
From that site, there are also some BMR calculators where you pop the numbers in and let it go....it will tell you (as long as you are honest with it) how many calories you should have in order to maintain (or lose) weight. Once you have done this, calculate your macronutrient levels and try very hard to keep to them. It is best to also add in at least 3 days of cardio while cutting weight as well.