Confringo (Blasting Curse) is not in the Wii version of Harry Potter and the Deathly Hallows – Part 1 or Part 2.
The Wii games are third-person cover shooters with a limited spell wheel: Stupefy, Protego, Confringo (Absent), Expelliarmus, Petrificus Totalus, Apparition (Part 2).
Confringo appears in:
No cheat/unlock adds it to Deathly Hallows Wii. The spell set is hardcoded per game design.