Same circuit
Most of the time, the bow and stern lights are on the same circuit. So, it shouldn't mess it up as long as you connect negative to negative and positive to positive. In other words, do not cross the circuits.The idea I have explained is to approach your situation the same way an electrician would if he had to wire a junction box to a breaker box by snaking a cable through conduit. Use the existing wire from the stern light to pull new wire through until you have enough to reach and connect. This is the best way I know. I did this with a 23 (not a Hunter) that I owned. I pushed a length of #10 wire with a small loop in the end through the stern light hole until I could reach it. Even then, I had to use the boat hook to reach way back under the cockpit to finish the pull. An assistant to continue to feed the wire in is a real help.This situation of yours requires some ingenuity.Recently, I had to replace the wiring in my H30. The bow light makes a blind run from the anchor locker to the cabinet behind the head. I connected new wire to the old with one butt connector. Then, I pulled the old wire through using the new wire. When the job was done, I installed new wiring just by pulling it through the boat with the old wire.Before I jumped into this, I checked the diagram of the H23. It seems possible to do it the way I suggest. Best of luck