title: Sort C++ Strings with multiple criteria
body: <p>I need to sort a C++ <code>std::vector&lt;std::string&gt; fileNames</code>. The fileNames are labeled as such</p>
  
  <p>YYDDDTTTT_Z_SITE</p>
  
  <p>YY   = Year            (i.e 2009 = 09, 2010 = 10)
  DDD  = Day of the year (i.e 1 January = 001, 31 December = 365)
  TTTT = Time of the day (i.e midnight  = 0000, noon = 1200)</p>
  
  <p>ZONE = Will be either E or W</p>
  
  <p>SITE = Four letter site name (i.e HILL, SAMM)</p>
  
  <p>I need the strings to be sorted by the following order: ZONE, SITE, YY, DDD, TTTT</p>