Path[in] Specifies the full path to the attachment file.FileName[in] Specifies the name of the attachment file. This parameter is optional and may be empty string, in which case the filename is obtained from the path.Description[in] Contains a user-defined description of the attachment file. This parameter is optional and may be empty string.Result[out, retval] A pointer to IPDFAttachment* pointer variable that receives the interface pointer of the object representing the added attachment.