title: C# application to import excel file content into a text file
body: <p>I have excel file with following columns</p>
  
  <pre><code>Field1 Field2 Field3, Field4
  ===============================
  123 4   abcd    efghi
  456 5   aabb    ffjjk
  789 7   ccdd    ababa
  </code></pre>
  
  <p>I would like to write a c# console application that 
  would read the excel file and create text file with the 
  following output</p>
  
  <pre><code>Field1 Field2 Field3, Field4
  ===============================
  123 4   ab  hi
  456 5   aa  jk
  789 7   cc  ba
  </code></pre>
  
  <p>in my console application, I should be able to specify per column in excel file, the start and, end columns. </p>
  
  <p>How would I write the application from start to finish?</p>