ATPVBAEN - The MS Analysis TookPak for Excel.
Yes, that will have to be on each machine on which you want to use its
features. If that's not easy, and you're only using the one function
(CurrentRegion) you might try writing something to do the job of
CurrentRegion. I'm not sure if the source code for it is available.
MAYBE if you check out the ATPVBAEN.XLA file  from VBA, it's got complete
unlocked sourcecode, but I wouldn't count on it, but it's possible...! I
haven't checked into it.
There are many ways to install templates, I can't go into it right
now...