Can I hard wire an IR remote directly into the receiver?
You can't do that directly because the LED signal is modulated on a (most commonly) 36 kHz or 38 kHz carrier, which is removed by the receiver. You could insert a circuit that removes the carrier, but from your question I guess that you don't have much experience in electronics, so I would't go that route.

Jodes' suggestion is by far the most practical. If you put the IR LED realy close, you might need to put a resistor in series with the IR LED to avoid overdriving the receiver (for a start, try 1k).