typedef struct _COMMCONFIG {
    DWORD dwSize;               /* Size of the entire struct */
    WORD wVersion;              /* version of the structure */
    WORD wReserved;             /* alignment */
    DCB dcb;                    /* device control block */
    DWORD dwProviderSubType;    /* ordinal value for identifying
                                   provider-defined data structure format*/
    DWORD dwProviderOffset;     /* Specifies the offset of provider specific
                                   data field in bytes from the start */
    DWORD dwProviderSize;       /* size of the provider-specific data field */
    WCHAR wcProviderData[1];    /* provider-specific data */
} COMMCONFIG,*LPCOMMCONFIG;