Hi:
I'm still wondering why you would NOT put the SAS Add-in on the desktop of folks who need to get stored process output in Excel.
At this point, I think that your issues are going to involve Tech Support. Generally speaking, the stored process server and workspace server do NOT have visibility of a single user's drive, except by UNC name or network name. Of course, THAT is not any information that is passed to the stored process server from the BI client applications. So although the client apps (such as EG or the Portal) do KNOW the metadata ID of the person who is submitting a stored process, that metadata ID does NOT carry personal PC information with it.
If you wrote a custom web application, using the HTTP protocol and the Stored Process Web Application, you could run your stored process and then send the streaming results back with a content-type header that would launch Excel on the local (requesting) machine. Again, installing the SAS Add-in for the end-users looks WAY quicker and more efficient to me than writing a custom SPWA app.
So, you did NOT say which client application your users were going to be "in" when they requested the stored process to run. If they don't have the SAS Add-in for Microsoft Office, then they must either be using EG or Web Report Studio or the Info Delivery Portal. I can't imagine that you're having them run stored processes that have been turned into jobs using DI Studio. Anyway, it sounds like you have some very particular requirements for your stored process. So, at this point, Tech Support is your best resource.
cynthia