title: regex match after word
body: <p>I would like to know how to capture text only if the beginning of a line matching a certain string... but i dont want to capture the begining string...</p>
  <p>for example if i have the text:</p>
  <blockquote>
  <p>BEGIN_TAG: Text To Capture</p>
  <p>WRONG_TAG: Text Not to Capture</p>
  </blockquote>
  <p>i want to capture:</p>
  <blockquote>
  <p>Text To Capture</p>
  </blockquote>
  <p>From the line that begin with BEGIN_TAG: not the line that begin with WRONG_TAG:</p>
  <p>I know the how to select the line that begin with the desired text: ^BEGIN_TAG:\W?(.*)</p>
  <p>but this selects the text &quot;BEGIN_TAG:&quot;... i dont want this only want the text after &quot;BEGIN_TAG&quot;</p>
  <p>I am using PCRE regex</p>