title: Write a "IF(A2) IS NULL" in excel with vba
body: <p>I currently write this formula in excel with VBA (it works)</p>
  
  <pre><code>Cells(r, c).Formula = "IF(COUNTIF($C:$C,C" &amp; r &amp; ")=COUNTIFS($C:$C,C" &amp; r &amp; ",$" &amp; col &amp; ":$" &amp; col &amp; "," &amp; col &amp; r &amp; "),""PRODUIT"",""ARTICLE""))"
  </code></pre>
  
  <p>Now, I'd like to add a condition to this formula:</p>
  
  <p>if the cell is blank; then return " " ; else, my actual formula</p>
  
  <p>So I tried this:</p>
  
  <pre><code>Cells(r, c).Formula = "=IF(C" &amp; r &amp; " = " " ;"";IF(COUNTIF($C:$C,C" &amp; r &amp; ")=COUNTIFS($C:$C,C" &amp; r &amp; ",$" &amp; col &amp; ":$" &amp; col &amp; "," &amp; col &amp; r &amp; "),""PRODUIT"",""ARTICLE""))"
  </code></pre>
  
  <p>I need some help, thanks in advance and sorry for my bad english.</p>