title: Cell Variable in google sheets formula
body: <p>I have a couple filtering formulas in Google sheet and would like edit them with another variable.</p>
  
  <p>The filter is for example (it shows all non empty cells form a row):</p>
  
  <pre><code>=FILTER('Data Input'!$A$3:$A$9781; NOT(ISBLANK('Data Input'!$X$3:$X$9781)))
  </code></pre>
  
  <p>The X should be a variable that I can set from a different cell. I was trying stuff like <code>INDEX</code></p>
  
  <pre><code>=FILTER('Data Input'!$A$3:$A$9781; NOT(ISBLANK('Data Input'!$INDEX(I13)$3:$INDEX(I13)$9781)))
  </code></pre>
  
  <p>but this just returns an error. Does anyone know how I can pass cell reference variables in a filter function?</p>