Podiatrists and other foot specialists--please help.?

I have been doing research on problems that have developed over the years from my poor gait. What I'm finding is that it is common for knees to lean inward when pronation is present and to lean outward when supination is present. However, I tend to supinate excessively and to compensate my knees have twisted inward. When I stand with my feet straight ahead, my knees both point inward at almost a perfect 45-degree angle. This condition is causing knee pain and it is becoming increasingly more difficult to get into and out of a squat. I am 37 and overweight by about 40 pounds. I'm trying to lose weight but am very frustrated because, due to my knee pain, I'm finding it difficult to exercise. Are there particular exercises or orthopedics that can be recommended to help correct my gait and return my knees to their proper position?