Thanks Matt, for your response.
I have called the number twice - and received a different response to my request.
One of them mentioned to post on this blog to see if it is indeed possible, and the other mentioned that I may need to download another evaluation copy using a different email address, or send a email request to saptrialsupport@sap.com. I have sent the email.
What would work best would be to receive a temporary license key for PowerDesigner - for the currently installed evaluation version. But not sure if such an option exists at this point.
-Jayesh