Best place to put application data?

Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData)

// assumes
// company is a pointer to a character sting containing company name
// appname is a pointer to a character string containing application name
// fname   is a pointer to a character string cintaining name of file to be created

#include <shlobj.h>   // for SHGetFolderPath
#include <direct.h>   // for _mkdir

char path[MAX_PATH];
SHGetFolderPath(NULL,CSIDL_COMMON_APPDATA,NULL,NULL,path);
strcat(path,"/");
strcat(path,company);
_mkdir(path);
strcat(path,"/");
strcat(path,appname);
_mkdir(path);
strcat(path,"/");
strcat(path,fname);

// path is now a character string which can passed to fopen