Two nice scripts that will allow you to make your character look at the camera in Daz Studio.
The first is from mcasual - mcLookAtTheCamera. Simply select your character's head an launch the script, check the options for neck/ chest/abdomen/hip as required and then click "do it". If the camera is animated, your character's gaze will track it so you can also use a dummy camera as a tracking object only.
The second script PointAt Fixer helps get better results when setting eyes to point at the camera in Daz Studio and poses Genesis characters eyelids to better match the eye movement.