The cable unlocks the hood latch behind the grill.  There is always a
way to get around a broken cable.  It may entail you looking up from
underneath the grill to see what's happening.  Generally, after the
cable releases the hood, there's a safety catch that you have to move
over with your finger before the hood can be lifted. You should be able
to initially release the catch with a screwdriver, from underneath.
Once the hood's open,  either fix the existing cable or fabricate a new
means of opening it from in front of the car.