I have the DRL enabled, I thought it was a low voltage applied to the high beams? Maybe I'm wrong, but if this is the case, then you would be losing your high beams.....
If it is a separate bulb, using a resistor is the right idea but there are some things to consider. Determine the wattage rating of the bulb - let's say it's 10 watts. To completely mimic the light bulb you will need a 10 watt resistor. If you measure the bulb resistance and use an equivalent 1/4 watt Radio Shack resistor, it will VAPORIZE as soon as power is applied. 10 watt resistors are MUCH bigger and harder to find.
In short, the resistor will need a wattage rating equal to or greater than the bulb. And the resistor WILL get hot, just as the bulb gets hot. Remember that a light bulb is REALLY a resistor that just happens to emit light as a by-product.