title: Get index of a specific item from list containing possible duplicates
body: <p>okay, I have a list of class objects like so:
      <pre><code>List&lt;fruit&gt; lst = new List&lt;fruit&gt;();
      lst.Add(orange);
      lst.Add(apple);
      lst.Add(grape);
      lst.Add(grape);
      lst.Add(orange);
      lst.Add(pear);
      lst.Add(apple);</code></pre></p>
  
  <p>I want to be able to ask the list something like
  <b>GetIndex("orange", 2)</b> and have it return (in this case) the index # for the second instance of object in question (position 4).</p>
  
  <p>This list will be dynamically filled, and it may not even have an orange to begin with.  If it does, I want the instance number of the second parameter.  So I can get the second orange, or get fifth mango, etc.</p>
  
  <p>list.IndexOf(orange) returns the first instance of any duplicates, so I need something else.</p>
  
  <p>Any ideas?</p>
  
  <p>PS: I failed to mention that the first param will be a string!</p>