Re-Download Elements for Retina Mac

I purchased Adobe Photoshop Elements 9 last year on B&H Photography website.  It came in the mail with a disc.  I installed it on my old Windows based system and it worked fine.  Since then, my PC has gone to hell and I purchased a MacBook Pro with Retina display.  Since this doesn't have the optical drive, I am trying to find a link to download it to my mac.  I can't find any links.  Does anyone know where I can get a link to download and then use the serial number on the back of the CD box?