Aperture Serial Number

I have been able to locate the e-mail receipt from the local Apple Retail Store sent to me following my purchase of Aperture 3 on Feb 13, 2010, for $199.00. How can I use this receipt to recover my Aperture 3 serial number? I have the box and all of the packaging material, as well as the disc. Today, I upgraded to the latest version of Aperture 3 and now I must provide the serial number in order to use the software. I have tried using every number I can find on the box to no avail. What next?

A German user provided an earlier e-mail I sent requesting the "password" for Aperture 3 that appeared to have the right answer to my question. I can't find his e-mail response to my first effort to use the Apple Support Community for Aperture.