title: Extracting subset of strings in R?
body: <p>Let's say I have a dataframe like</p>
  
  <pre><code>Group            Score
  Duck QuackDUC    0.343
  Ten TopTEN       0.198
  ** -Men MaleMEN  0.350
  y -Rural AreaRU  0.888
  Maple TreeMAP    0.468
  Man NavyMN       0.150
  </code></pre>
  
  <p>I want to extract the word in each <code>Group</code>, which is the string after the space ' ', and before the 2-3 char string in all caps. That is, I want the result to be</p>
  
  <pre><code>Group Score
  Quack 0.343
  Top   0.198
  Male  0.350
  Area  0.888
  Tree  0.468
  Navy  0.150
  </code></pre>
  
  <p>How do I extract these words?</p>