title: How to reuse a formula in another cell but change the referenced columns
body: <p>I have a formula in a cell:</p>
  <pre><code>=AVERAGE(I8,I17,I29,I39,I49,I62)
  </code></pre>
  <p>In another cell, I want to take reference this formula and re-use it, but change all the <code>I</code> to, say, <code>B</code> like so:</p>
  <pre><code>=AVERAGE(B8,B17,B29,B39,B49,B62)
  </code></pre>
  <p>I want to do this in an automated fashion like simply substituting all the occurrences of <code>I</code> with <code>B</code> or <code>F</code> , w/e, so that I only have 1 original formula I need to modify to change all the other dependent cells.
  How can I do so?</p>