Honestly, I think it will do two very small things aerodynamically. Add a bit of drag from disruption of airflow and air passing through the vehicle in some manner rather than over the surface of it, which is lower drag (like all openings in the front of vehicles - hence the active shutter tech we are starting to see) and probably yes, create a bit of net lift: A few hands widths back from the top leading edge of the front end (and extending backwards maybe half the hood- depending on design) is a low pressure area -taken advantage of by the draw out vents you see in the hoods of many race vehicles (the new viper GTS Rs spring to mind) these vents actively suck air through the heat exchangers at the front of the vehicle and reroute most of the air that would have to find its way out of the engine compartment by other means all while creating drag- ...reroutes it back over the vehicle and in this way also increases the airflow to the rear wing. But area in front of that is a high pressure area pushing down on the angled surface of the bumper and if you remove some of that surface area...
Both of these effects would be very minimal to the point of arbitrary in your case.
Anyway, thats my analysis and
Edit/correction: The low pressure area over the hood actually starts AT the top leading edge of most vehicles. So its entirely possible that the area you are proposing putting those ducts is a LOW pressure area
