title: adding value to a cell reference
body: <p>I'm having multiple sheets in an excel file </p>
  
  <p><code>sheet1</code>  contains some data from <code>A1 to A100</code> </p>
  
  <p><code>sheet2</code>  in this sheet <code>row1</code> contains the data with numeric value</p>
  
  <p>in <code>sheet2</code> if <code>A1</code> contains the 0 <code>A3</code> should be the value of <code>A1</code> of <code>sheet1</code></p>
  
  <p>in <code>sheet2</code> if <code>A1</code> contains the 30 <code>A3</code> should be the value of <code>A1+30</code> that is <code>A31</code> of <code>sheet1</code></p>
  
  <p>Any idea how to get the described behavior?</p>