title: Excel data validation by combining multiple conditions
body: <p>Can i do excel validation formulas with multiple conditions?
  I have one column where i want 
  1) unique values 
  2) All the values have to be 10 characters(leading zeroes allowed)
  3) All have to be numbers</p>
  
  <p>I can get unique values with the below formula:</p>
  
  <pre><code>=COUNTIF($G:$G,G2)=1
  </code></pre>
  
  <p>How do I add the other two conditions?</p>
  
  <p>If i set the type as number, the leading zeroes are not displayed.</p>