It sounds like your shifter cable needs to be replaced. Here's a link where I found some info from a few other people who have dealt with this before: http://www.lhforums.net/forums/showthread.php?19982-Stuck- In-Park Good luck!
I had a similar problem. We replaced the shifter cable as referenced above by Michael.
Search Chrysler Concorde Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Chrysler Concorde Experts