title: C++, Searching strings in file using own criteria
body: <p>I am a beginner in C++, I want to create criteria to search the data into the file.
  I need to find every sentence which contains <code>(3letters) (3-2letters) (value with at least 3 digits)</code></p>
  
  <p>Example of that sentence would be <code>ANT TRY 324</code></p>
  
  <p>Right now I am using <code>sentence = find(my_cell, "string")</code></p>