title: Limiting the sed search to 2 nd column in a file
body: <p>Below is the content of ma file (sample.txt):</p>
  
  <pre><code>CQUAD4   5600000 560005  5602371 5602367 5602374 5602372 0.     -1.75
  CQUAD4   5600003 560005  5600000 5602367 5602374 5602372 0.     -1.75
  </code></pre>
  
  <p>Am using the below command:</p>
  
  <pre><code>sed -i "s@\(\s*\w*\s*\)\(5600000\)\(\s*\)\([0-9]*\)\(.*\)@\1\2\36000   \5@g" sample.txt
  </code></pre>
  
  <p>I want to restrict the pattern matching <code>5600000</code> to only second column and then do a replace with '6000   '.</p>
  
  <p>Can somebody help me...please</p>