title: FInd a character in a string in column in dataframe and give decisions in R
body: <p>I have data in following format</p>
  
  <pre><code>     Loss        
  --------------------------
       R0RKE         
       R0HKE         
  </code></pre>
  
  <p>I want R script to return me after applying logic: If 3rd character in string
  is 'R' then Yes, if its 'H' then No, else leave blank</p>
  
  <pre><code>           Loss
  --------------------------
             Yes
             No
  </code></pre>