driving lights and headlight bridge

I've got a car with separate bulbs for high and low beams (9005/9006) and I also have a set of driving lights installed. My headlight switch has 3 positions: Off, parking lights, headlights & parking lights. With the headlights on, I have the option of low beams or high beams. While one is on, the other shuts off. I would like the following behavior: When the switch is turned onto the parking lights position, the driving lights come on as well. They would therefore also be on in the headlights position. When I have the car's low beams on, only the low beams illuminate. But when I switch to high beams, the high beam lights come on in addition to the lows. This way I can still have the road in front of me lit up. I have a standard automotive relay which I had been using for my driving lights before I swapped out my composite headlights this afternoon. I have since become confused as to the proper wiring of this relay. 30 is the +12V from the battery, yes? On which line should I connect the "trigger" wire from the parking lights? Is it 86, and then I connect the + line of the driving lights to 87? And 85 is ground? The other reason I am posting this is to find out if there is a better way to achieve this behavior than using two relays independently wired. Basically, if this were your car, how would you go about doing this? Thanks!