Setting up regular expressions in Google Analytics to track common goals and conversions can be a real pain in the ass. The more complex the site and the url structure, the more complex the expression sometimes is. Google provide very little information on how to set up regular expressions in analytics and its hard to find good resources on the net.
Regular expressions can also be very confusing and even good coders sometimes struggle to figure out how to get the best from it. Some time ago i came across this site that helps put it into layman's terms http://www.lunametrics.com/Regular Expressions. Have a good read of this site as it can really help in setting up your regular expressions.
After you have created your regular expressions one of the best ways to test them is in Google Analytics under the "Content" menu then click on the "Top Content" sub menu. You can then use the "Find URL:" search box at the bottom of the page. Type your regular expression in here and if it returns the results that you targeted in your expression then your on the right track.