You may be able to set one of the User Modes to do this, but I'm not sure and I don't have my camera in front of me (it's in the family room and the wife is napping).
Got to be honest, but with a camera like the D600 I'm really not sure how in-camera HDR will buy you anything. The dynamic range is so good that you can do more in post after shooting RAW, including single image HDR tone mapping, that will likely beat anything you'll get out of the jpeg produced by in-camera HDR.
Are you looking to avoid shooting RAW, or minimize post-processing?