The MCI_LOAD_PARMS structure contains the information for MCI_LOAD message. When assigning data to the fields in this data structure, set the corresponding MCI flags in the dwFlags parameter of mciSendCommand to validate the fields.
typedef struct {
    DWORD  dwCallback;
    LPSTR  lpfilename;
} MCI_LOAD_PARMS;The MCI_LOAD_PARMS structure has the following fields:
dwCallback
The low-order word specifies a window handle used for the MCI_NOTIFY flag.
lpfilename
Specifies a far pointer to a null-terminated string containing the filename of the device element to load.
MCI_LOAD