const save = () => {
    wjcGridXlsx.FlexGridXlsxConverter.saveAsync(
(....)
        formatItem: exportFormatItem ,
(...)

  const exportFormatItem = (args) => {
    var p = args.panel,
      row = args.row,
      col = args.col,
      xlsxCell = args.xlsxCell;
    if (p.cellType === wjGrid.CellType.Cell) { //셀 영역이고
      if (p.columns[col].binding === 'id') { // id 열이면
        (....)
          xlsxCell.style.format = '@'; //텍스트 서식 적용
        }
      }
    }
  };