How to get the white out of my exterior brick

I own a brick house, that has white aluminum siding on the top cable ends of both sides of the house. There seems to be a white stain on the brick just below the aluminum which I'm assuming is coming from that aluminum white finish that is 35 years old and has oxidized a bit. I've tried using my pressure washer to remove the stains from the brick, but it just won't budge.
What can I use ???