automatic transmission problem

the vehicle will only go in reverse, all forward gears act like it's in neutral. can anyone give me an educated guess as to what might be the cause?

What year, engine, mileage is your car?

1999, 75005 miles, and a 6cyl

I have a 92 pontiac bonneville, way different car I know, but My ex ran over a boulder and put a dent in my tranny pan that was deep enough to bend closed one of the little metal tubes that lead into my cervo as well as break off a part of the mount for that hose. there were a total of 3 metal tubes coming out of the cervo one was bent shut the other fallen out of its hole and the other still hooked up. My car would still drive in reverse but basically was in neutral when you put it into any of the forward gears. I changed the cervo {snagged one off of a buick regal} and the car runs fine. Dont know if this helps any but it might point you in the right direction.