DCOM permissions issue in server 2008

I am running a task in the Task Scheduler that logs in as a domain user and runs a custom program to do things with Excel spreadsheets.  If I log in as that user normally, I can run the program just fine.  When run from the Task Scheduler, however, the program returns an OLE error "Access is Denied".  If I use an admin account in the Task Scheduler instead of the domain user, the program runs fine.  (That may end up being an acceptable workaround but I'm not sure yet.)

So, in short, there's some sort of permissions issue with the domain user trying to create an Excel.Application object when run as a batch job through the Task Scheduler.  

Looking through the Event Viewer, I find this entry:

The machine-default permission settings do not grant Local Activation permission for the COM Server application with CLSID
{00024500-0000-0000-C000-000000000046}
 and APPID
Unavailable
 to the user DOMAIN\user SID (S-1-........) from address LocalHost (Using LRPC). This security permission can be modified using the Component Services administrative tool.

That CLSID does correspond to Excel.Application which is the object my program is trying to instantiate.

I've seen other threads referring to this Component Services administrative tool.  I'm unfamiliar with it, but I've looked through it and can't find anything referencing Excel or that CLSID anywhere in it.