Microsoft handles all activation and key, lost media issues. So far Microsoft has not given anyone else the capability to replace or fix a key.
But why not try what you asked and if it fails, make the call.
I purchased Office 2007 Home and Student and activated it on my Toshiba which had a trial version pre-loaded. I have since had to reimage my computer and although I have the product key, I do not have the disk. When I tried my product key, a message that the key does not have a 1 in it--which it does. If I remove the trial that came with it; can I download Office 2007 and then use my product key?