How can I actually play iCloud/iTunes on my MacBook Pro?

Question

I use a MacBook Pro with a 2.53 GHz Intel Core 2 Duo, running Snow Leopard (10.6.8).  I haven't updated to Lion because I'd have to re-purchase ProTools in order to do that, and ProTools was the whole reason I upgraded to a MacBook Pro to begin with. 
A few days ago, I purchased a subscription to iTunes Match because I store all of purchased music on an external hard drive, and I got nervous when a friend's external drive failed.  I also wanted a way to play purchased music on my laptop when I'm somewhere with wi-fi, but I don't have my external hard drive with me. 
After a lot of stopping and starting, I finally uploaded or matched all of my music to the cloud.  I feel good knowing it's safe (or as safe as it can be).  But I don't understand how to play it on my computer without my external hard drive.  When I double-click on a track without the external hard drive connected, I get the usual exclamation point and the offer to try to locate the original file. 
I found a tutorial somewhere that suggested I go to www.icloud.com, but when I enter my Apple ID there, it tells me that I need to set up a device for iCloud, which I obviously have, otherwise where would all of that music have gone? 
What am I supposed to do here?  Did I just unwittingly purchase membership for a service I could only use if I was using either a Lion-operated laptop or an iPhone? 

Answer 1

I did find a workaround, but it wasn't precisely what you suggested.  I didn't create a second user account, but I did create a second library.  I saw that a few other people have reported this frustration, so I'll write out what I did. 
1.  Close iTunes
2.  Click on the iTunes icon in your dock
3.  Immediately hold down the "option" key
4.  You'll be given an option to either choose or create a library in your music folder.  Choose create.
5.  Name the new library.  I named mine "Magic Cloud Library," because I don't want to mistake it for one of the libraries that my computer automatically creates. 
6.  Next, turn on iMatch.  You'll be asked to log in.  Do that. 
7.  I think I was asked one more obvious question, but then my music library loaded, and I was able to stream from the cloud on the computer that was the original source of the music. 
Now, when I want to listen to my music without the external hard drive connected, I just open iTunes, hold down "option," choose the "Magic Cloud Library," and I'm in business.  I don't have to switch users or identities.