C++ Get country code

Question

I'm trying to get the country code (example: "UK" or "SI" or "GER") via GetGeoInfo().

    GEOID GetUserGeoID(GEOCLASS_NATION);

Currently getting the value 16 from the above function ^ but looking in the table there's no number 16.

https://msdn.microsoft.com/en-us/library/windows/desktop/dd374073(v=vs.85).aspx

I know it's only 3-4 lines of code but I can't seem to figure it out on my own. Any help would be appriciated.

EDIT:

GEOID myGEO = GetUserGeoID(GEOCLASS_NATION);
int sizeOfBuffer = GetGeoInfo(myGEO, GEO_ISO2, NULL, 0, 0);
WCHAR *buffer = new WCHAR[sizeOfBuffer];
int result = GetGeoInfo(myGEO, GEO_ISO2, buffer, sizeOfBuffer, 0);

Got it to display my country number but I don't know how I'd transform it into an ISO code.

Answer 1

To get the country ISO:

GEOID myGEO = GetUserGeoID(GEOCLASS_NATION);
int sizeOfBuffer = GetGeoInfo(myGEO, GEO_ISO2, NULL, 0, 0);
WCHAR *buffer = new WCHAR[sizeOfBuffer];
int result = GetGeoInfo(myGEO, GEO_ISO2, buffer, sizeOfBuffer, 0);
wcout<<buffer;

Thanks to @Christophe and @Thomas.