Pereira,
You can try substitution, but even in that you need to know which profit center you would be using. And since you are saying that you would know it only during posting, it is dicey.
Only advantage is, you can specify a profit center group/SET in subsitution, and can then keep changing the profit centers in the group/set before executing the statement. But the process becomes messier and unmanagable though giving flexibility.
THanks.