ahhh so your body kind of stores the protein and carbs a different way and uses it as your muscle fibers expand, right?
Your muscles are made out of protein, water, and stored glycogen (a ready-to-use carbohydrate source for energy), so both protein (amino acids) and carbohydrates are needed to build muscle tissue. In the case of having more than enough protein and carbs in the blood, they will be broken down and reconstituted into fatty acids and stored as body fat. Once protein and carbs are made into fat, they can't be changed back into protein. So, once these nutrients are "stored" they won't be used to build muscle tissue. Feeding muscle growth is something that is done with fresh nutrient intake, not body tissue "recycling" so to speak.
Your body will also store any excess protein and dietary fat as body fat. The only way to get your body to use these extra calories to expand muscle tissue instead of storing them as body fat is to lift really heavy s**t several times, then wait a minute and do it again, and repeat for your various body parts.
The key here is you need to push your body into adapting to better accomodate the stress you're putting on it, in this case making your muscles bigger/stronger so it's easier to lift the things you're asking it to lift. Lift heavy, especially on your main compound lifts, and give your muscles time to rebuild and those extra calories will go to muscle instead of just fat.
Things you can do to enhance the muscle building ability of your body are to make sure your nutrition is in check (1-2g protein/lb of bodyweight, 0.5-0.8g good fats/lb of body weight, and plenty of CLEAN COMPLEX CARBOHYDRATES like brown rice, oats, and green veggies and some limited fruits). Also limit your comsumption of refined sugars as these will, over time, make your muscles insulin resistant. What this means is that when nutrients are available in your blood stream they go to either muscle or fat, whatever wants to grab them first. If you're insulin resistant your muscles will pass up the food and the only thing that grows then is your waistline (why so many diabetics are overweight and why being overweight can make you diabetic).
So, to recap:
Make a good nutrition plan and follow it
Eat a lot and eat often
Hit the weights with 110% effort every time