Choosing your character.

I have tried searching for this abilty to choose which character you wish to be on the fps.starter. I bought the adam pack and I want the ability on multi-player to choose who's who. I may be inputing the wrong info in the search bar but I haven't been able to find the answer.

If someone could maybe refer a forum or resource that they have tried I would appreciate it. If you have the solution and wish to share it that would also be appreciated. Thank you.