What I generally do with such problems is break them into individual requirements in my code, then later attempt to put it all in one statement if possible/desired(I usually don't desire it).

So it becomes a check and pass unless fail sequence of statements in my code. It is a lot easier for me to trouble-shoot that way. Those who are great at RegEx's may snicker at this approach, but hey, it works and I find it a lot less frustrating..

Hope that is helpful...