title: Need help with Excel 2007 Formula - Many to many update
body: <p>I'm experienced with database development, but not so much with Excel. I'm looking for help writing an Excel formula that would help my client's spreadsheet behave like a database.  This is what I'm looking to do, but I can't figure out how to write it in Excel 2007:</p>
  
  <p>"If Q4 (on sheet 2) contains A2 (on sheet 1), append A1 (on sheet 1) with Q5 (on sheet 2)"</p>
  
  <p><strong>Some factors:</strong></p>
  
  <p>1) This formula may find multiple instances of A2, so it should not stop after finding the first match</p>
  
  <p>2) The values, as they are created in A1, should be separated with comma and space</p>
  
  <p>3) This is a many to many relationship between Q4 and A2</p>
  
  <p>Thanks for any help with this.  I've tried vlookups, match, if statements, but they all fall short in one way or another.  </p>