No - the other way round - if power.cgi is in a different directory to Test.pm, you'll need an absolute path to it ("/httpd/whatever/") or a relative path that will find it ("../../httpd/whatever").
pfaut's point is that if you use a relative path, and then move script.cgi to *somewhere else*, the relative path won't work, so you're probably safer using an absolute path.
You've sussed it about @EXPORT and @EXPORT_OK though. :)
Cheers
Ben.