Con VB6 avevo trovato questo codice...

' This creates a Root entry called "MyApp".
sKeyName = "Prova"
sKeyValue = "Prova"
ret& = RegCreateKey&(HKEY_CLASSES_ROOT, sKeyName, lphKey&)
ret& = RegSetValue&(lphKey&, "", REG_SZ, sKeyValue, 0&)

' This creates a Root entry called .BAR associated with "MyApp".
sKeyName = ".prova"
sKeyValue = "Prova"
ret& = RegCreateKey&(HKEY_CLASSES_ROOT, sKeyName, lphKey&)
ret& = RegSetValue&(lphKey&, "", REG_SZ, sKeyValue, 0&)

' This sets the command line for "MyApp".
sKeyName = "Prova"
sKeyValue = path & "Prova.exe %1"
ret& = RegCreateKey&(HKEY_CLASSES_ROOT, sKeyName, lphKey&)
ret& = RegSetValue&(lphKey&, "shell\open\command", REG_SZ, _
sKeyValue, MAX_PATH)

' This sets the icon for the file extension
sKeyName = "Prova"
sKeyValue = path & "Prova.ico"
ret& = RegCreateKey&(HKEY_CLASSES_ROOT, sKeyName, lphKey&)
ret& = RegSetValue&(lphKey&, "DefaultIcon", REG_SZ, _
sKeyValue, MAX_PATH)

' This notifies the shell that the icon has changed
SHChangeNotify SHCNE_ASSOCCHANGED, SHCNF_IDLIST, 0, 0

Ma non ho trovato il corrispettivo in visual c++,sapete se c'è una classe che può fare questo?

Ciaooooo