I have an app that checks for its classname to prevent launching a 2nd
instance but I really need to launch a 2nd instance of it. Therefore I'd
think that I either need to change the classname of the running app or
change the classname of the 2nd instance while I launch it. Any ideas how to
accomplish this?

I've checked into GetClassInfoEx and GetClassLong and can retrieve all the
class information of the running application but SetClassLong doesn't allow
me to change the name. I also looked into RegisterClassEx where I can set
the classname in the WNDCLASSEX structure but don't understand how (if
possible) to use it with CreateWindowEx. CreateProcess doesn't seem to have
an option of setting the classname either.

I'd appreciate any help you can give me.