For a start you can do:
Every Tick
----Scroll to Position X = lerp(scrollx, character.X, 0.05);
Position Y = lerp(scrolly, character.Y, 0.05);
Change de last value , in this case 0.05 to values between 0 and 1 where 0 doesn't move at all, 0.5 moves at 50% velocity, 1 moves at 100% velocity , that is, same velocity of character.