title: Relative click location in a DataGridView Cell
body: <p>I have been looking a solution for my problem.<br>
  I'm trying to detect a click, when this click is performed in the last <code>20px</code> of my Cell, relative position (starting from left).</p>
  
  <p>I have reviewed some similar situations without success because they detect the left upper corner <code>x, y</code> point of the clicked cell.</p>