title: Regex Pattern Matching Concatenation
body: <p>Is it possible to concatenate the results of Regex Pattern Matching using only Regex syntax?</p>
  
  <p>The specific instance is a program is allowing regex syntax to pull info from a file, but I would like it to pull from several portions and concatenate the results.</p>
  
  <p>For instance:</p>
  
  <p>Input string: 1234567890</p>
  
  <p>Desired result string: 2389</p>
  
  <p>Regex Pattern match: (?&lt;=1).+(?=4)<strong><em>%%</em></strong>(?&lt;=7).+(?=0)</p>
  
  <p>Where <strong><em>%%</em></strong> represents some form of concatenation syntax.  Using starting and ending with syntax is important since I know the field names but not the values of the field.</p>
  
  <p>Does a keyword that functions like <strong><em>%%</em></strong> exist?  Is there a more clever way to do this?  Must the code be changed to allow multiple regex inputs, automatically concatenating?  </p>
  
  <p>Again, the pieces to be concatenated may be far apart with unknown characters in between.  All that is known is the information surrounding the substrings.</p>
  
  <p>2011-08-08 edit: The program is written in C#, but changing the code is a major undertaking compared to finding a regex-based solution.</p>