title: Boolean logic in a single regular expression - possible?
body: <p>Can we put into a single regular expression , boolean logic : line starts with 'a' or 'b' . 
  Question is triggered by using FileHelpers utility which does have a text box "Record Condition Selector" for  "ExcludeIfMatchRegex" . Utility is written in C#. 
  ^a - works , just don't how write down ^a OR ^b</p>