Calorie theory

Just wanted to run this by the calorie experts on here...Ive developed a new way of doing things after much ups and downs.
If I am of a low body fat percentage now and want to add weight in muscle, can I choose a bodyweight 2-3kgs above what I am at now, and eat the required amount of calories for that bodyweight. So in theory, whilst training, I will get to that bodyweight probably with fat at first, but if I stick to the routine and calorie intake, the fat should go as I train - increasing muscle weight but staying at the required bodyweight, eating only the calories required to fuel the bodysize.
Have I lost the plot or does it make sense?
Obviously when at that weight you would not want to increase the weights to put on more muscle thus changing the bodyweight, or it would take more food..but if at the same weights except higher reps, minimal growth but toning should occur. The professor has spoken:pac: