There is some wonderful software out there that would help easily... HDR techniques etc..
But If all you have is an old Photoshop package to work with..
First, Shooting into the sun is always difficult even under the best of conditions, and I didn't really understand your composition, so I re-composed and have less to have to clean up..
You can use the Marquee or Lasso tool to bound and isolate your washed out area, then work on it without messing too much with the rest of the shot..
This was done in a minute, isolating the washed area with a square marquee, then the burn tool to feather the sharp edges.. add little contrast, color saturation, and resharpen..
A little time spent on it and I'm sure that you can do better..