To use the miles on a *A partner it does not necessarily have to be a "Star Alliance Upgrade". That *is* one way to do it, but you can search Continental's reward inventory as well. This will often have various star alliance partners included, but booked through Co.com under the OP program.

For instance, if you go to co.com and search for a reward from Newark to Munich you might want Continental direct flight EWR-MUC but you might instead find EWR-FRA-MUC on Lufthansa, bookable on Co.com.