The DPCREDENTIALS structure is defined as :-

struct DPCREDENTIALS {
DWORD dwSize;
DWORD dwFlags;
union {
LPWSTR lpszUsername;
LPSTR lpszUsernameA;
};
union {
LPWSTR lpszPassword;
LPSTR lpszPasswordA;
};
union {
LPWSTR lpszDomain;
LPSTR lpszDomainA;
};
}