Thanks a lot, CirKutz. It worked like a charm.
As I said in my post, I had looked for SuperPower already in GameCopyWorld, without success; I genuinely believed the game wasn't supported in there.
In fact, this is part of the "game index" page for the letter S:
(...)
Stronghold
Stronghold Deluxe
Submarine Titans
Sub Command
Sudden Strike
Sudden Strike Forever
Sudden Strike 2
Summoner
Die Rache der Sumpfhühn
Super 1 Karting Sumulation
SuperBike
Superbike 2000 - EA
Superbike 2000 - Castrol Honda
Superbike 2001
Supercar Street Challenge
Supreme Snowboarding
Survivor
Suzuki Alstare Extreme Racing
S-G Erikssons World manager
SWAT 3
Swedish Tour Car Championship
Swedish Tour Car Championship 2
(...)
As you can see, there's no trace of the game in there, so I thought it was nowhere to be found in GCW. My mistake.