Caro-Kann Exchange Variation

What setup will be the best for black if he is a positional player after 4 Bd3?

Why should it be different if he is a positional player?? (There are many possibilities after 4.Bd3 that will change your plan).

A positional player always look deeper into a position. I'm a positional player and this is what I would think when I play against a strong opponent:

1) I know that I'm not required to attack unless my opponent doesn't know what he is doing. I will build a better pawn structure, put pieces in positions flexible enough to answer any possible problems given by my opponent

2) I will pay attention to the structure of my pawns, compare it to my opponent's pawn structure, to ensure that when I can at least successfully defend the midlegame I would have a winning endgame.

3) To defend successfully I need to think of the best position for my pieces so that it can easily answer any problems given by my opponent (including counter-attack possibility). Like in many other opening, especially when Black is a little bit behind in development, I will prioritize ...Nc6 and ...Nf6 (or may be ...Nh6).

4) Now, I look at the position after 4.Bd3 to determine what "setup" to choose.

I have an open c-file, and I expect my opponent's c-pawn to stay at c3 to support his d4. I have a chance at Queenside, not to attack but to develop a winning endgame. I have to defend the kingside, efficiently. There is one key feature that I will use to achieve both of these goals: I will put my dark bishop to control the main diagonal!! (through ...Bg7).

BTW, I hope that you understand why the fianchettoed bishop is an important key element for winning such position

I've read that 5. Qc7 is playable as well. Which is my preference when faced with the exchange variation.