You have to be carefull when posting MSDN links because the address bar rarely contains the URL of what you're looking at.
I think you meant to post the URL for WSAAsyncGetHostByName()
From MDSN, WSAAsyncGetHostByName() parameters
[out] Pointer to the data area to receive the hostent data. The data area must be larger than the size of a hostent structure because the specified data area is used by Windows Sockets to contain a hostent structure and all of the data referenced by members of the hostent structure. A buffer of MAXGETHOSTSTRUCT bytes is recommended.
hostent *abc = (hostent*)hostentBuff;