Make sure you are discussing either:
1. Aerodynamic effects
Where power demands about the main rotor do not change either down or into wind. [Tail rotor effects are negligible].
To appreciate the scenario more, consider a helo with the tail cone and tail rotor removed, simply a rotor disc rotating with a lump of metal dangling underneath. The rotor doesn't know (nor cares) where the wind comes from, it's always the same result.
or,
2. Airframe effects.
Profile drag or parasite power etc. Is the entire slab side of the helo impacting the wind direction, or is it head on. Is the wind from astern impacting on the top surface of the stabilisers pushing it down? Is the astern wind pushing the downwash ahead of and away from the helo??
1: wind direction no effect.
2: wind direction major effect.