title: Using a workbook with VBA to open a saved workbook, modify that pre-existing workbook, save and close
body: <p>I would like to be able to run a VBA command in an Excel workbook that will open a saved, existing workbook at a specified location (<code>Desktop\ThisBook.xlsx</code>).</p>
  
  <p>After opening the <code>ThisBook.xlsx</code>, the command will take numerical values from specified cells in the VBA workbook (A1), add them to an existing cell in <code>ThisBook.xlsx</code> (something like <code>ThisBook.xlsx A1 = ThisBook.xlsx A1 + ActiveDocument A1</code>) and save them where the <code>ThisBook.xlsx data</code> was.</p>
  
  <p>Finally, overwrite the previous save file for <code>ThisBook.xlsx</code> and overwrite the new data.</p>