title: Excel Creating a List from Beginning and End number AND tags
body: <p>I am trying to create a list from an index of grouped values.<br>
  This is very similar to <a href="https://stackoverflow.com/questions/635800/how-to-create-a-list-from-beginning-number-and-end-number">this</a>, however my groups also have "tags" on then that complicate the listings.</p>
  
  <p>Here is an example of my INDEX tab:</p>
  
  <pre><code>  | A  | B  | C  |  D  |
  -------------------------
  1 | 1  | 1  | 1  | CV  | 
  2 | 1  | 2  | 2  | IS  |
  3 | 1  | 3  | 3  | IS  |
  4 | 2  | 4  | 5  | GN  |
  5 | 2  | 6  | 7  | PS  |
  6 | 4  | 8  | 11 | SQ  |
  7 | 2  | 12 | 13 | SS  |
  8 | 1  | 14 | 14 | AT  |
  9 | 15 | 15 | 29 | AT  |
  10| 4  | 30 | 33 | TYP |
  </code></pre>
  
  <p>Where A is the number of pages, B is the first page, C is the last page and D is the tag. I would also like to add columns such that I can keep a running tally of the tags.</p>
  
  <pre><code>  | A  | B  | C  |  D  |  E   |  F   |
  ---------------------------------------
  1 | 1  | 1  | 1  | CV  | CV1  | CV1  |  
  2 | 1  | 2  | 2  | IS  | IS1  | IS1  |
  3 | 1  | 3  | 3  | IS  | IS2  | IS2  |
  4 | 2  | 4  | 5  | GN  | GN1  | GN2  |
  5 | 2  | 6  | 7  | PS  | PS1  | PS2  |
  6 | 4  | 8  | 11 | SQ  | SQ1  | SQ4  |
  7 | 2  | 12 | 13 | SS  | SS1  | SS2  |
  8 | 1  | 14 | 14 | AT  | AT1  | AT1  |
  9 | 15 | 15 | 29 | AT  | AT2  | AT16 |
  10| 4  | 30 | 33 | TYP | TYP1 | TYP4 |
  </code></pre>
  
  <p>Note that the tag could occur multiple times and it may not be in sequential rows.</p>
  
  <p>Here is what I want this to look like for my LIST tab:</p>
  
  <pre><code>  | A   |
  ---------
  1 | CV1 |
  2 | IS1 |
  3 | IS2 |
  4 | GN1 |
  5 | GN2 |
  6 | PS1 |
  7 | PS2 |
  8 | SQ1 |
  9 | SQ2 |
  10| SQ3 |
  11| SQ4 |
  and so on...
  </code></pre>
  
  <p>How do I add the additional columns to the INDEX tab via formulas?<br>
  How do I create the LIST via formulas? (...is this even possible?)</p>