title: Regular Expression match but not include
body: <p>I'm trying to use regular expression to only select the bolded (minus the *'s) based on the below string (carriage returns are in the string).  Every string that I want to select it out of begins with ISA.  I've been trying to work with this, <code>(?&lt;=ISA\\*)(\w*)</code>, but whenever I start adding additional characters to exclude in the <code>(?&lt;...)</code> part, I no longer find any matches.</p>
  
  <p>ISA*00*         *00*          *ZZ*SOME STRING  *ZZ*99999999  <strong>*130605</strong>* 2239*|*00501*000000001*0*P*></p>
  
  <p>REF*TJ*12345677*</p>
  
  <p>REF*PQ*23432211</p>
  
  <p>LX*1</p>