linking across projects

Reaching out to whoever might have an idea if this is possible, but has anyone been able to link test cases across projects?  We created a project as a depository to hold all of our test cases and then we test any enhancements and releases in another project.  Each month we will be copying over the test cases, basically creating a new version each time.  I'm concerned after many months if a test case fails, that had passed in previous months, it will waste a lot of time trying to locate where each version of that test case is located to see if the fail impacts other testing. 

If we use one project to house all test cases and perform testing, it is possible to link different versions of one test case, if they are cloned, but I do not believe it is possible when you copy test cases from project to project.  Unless someone knows how.

Any assistance is greatly appreciated.