/// <summary>
        /// DataGridViewの列オブジェクトから、Excelの表示形式を取得します。
        /// </summary>
        /// <param name="gridColumn">DataGridViewの列オブジェクト</param>
        /// <param name="range">設定対象セル</param>
        /// <returns>Excelの表示形式</returns>
        private void SetFormat(DataGridViewColumn gridColumn, ref dynamic range)
        {
            var valueType = gridColumn.GetValueType();
            string gridFormat = gridColumn.DefaultCellStyle.Format.Convert(format => format.Replace(@"\\", @"\"));
            string numberFormat =
                (true == valueType.IsNumeric()) ? this.GetNumericExcelFormt(gridFormat) :
                (typeof(DateTime) == valueType) ? this.GetDateTimeExcelFormt(gridFormat) :
                (typeof(string) == valueType) ? this.GetStringExcelFormt(gridFormat) :
                                                this.GetOtherExcelFormt(gridFormat);

            if (null != numberFormat)
            {
                range.NumberFormat = numberFormat;
            }

            return;
        }