Is it possible to use a subdomain that uses the staging hosting files directory so that we can continue to run our live site www.exampledomain.com and still be able to go to test.exampledomain.com which would use the staging files? 

We currently have our test subdomain pointing at shopping.netsuite.com, however when you enter test.exampledomain.com it redirects to www.exampledomain.com.

I think this may be because our primary web site url is set to http://www.exampledomain.com

So is what I want even possible.  I'm aware of the sandbox account, but if it's possible we'd rather not pay the high fees to test things.  I also know you can make a tab only visible to yourself etc... but I'd prefer a whole test site.  Any help is appreciated.  Thanks.