This should work:
Create an object called 'Camera'
Add the ScrollTo behaviour to it.
Add another two objects called Left_C and Right_C, put them where you want the camera to stop moving.
Add this to an event sheet and make sure the event sheet always runs while the player is moving around:
For every tick
If Player.X > Left_C.X (and) Player.X < Right_C.X
Camera.X = Player.X
If Player.X >= Right_C.X
Camera.X = Right_C.X
If Player.X <= Left_C.X
Camera.X = Left_C.X