Office Scripts

link - learn.microsoft.com/en-us/office/dev/add-ins/excel/excel-add-ins-worksheet-functions

Calling built-in worksheet functions

Excel.run(function (context) { 
   var _sheet = context.workbook.worksheets.getActiveWorksheet(); 
   var _column = _sheet.getRange("A:A"); 
   var _rowMatching = context.workbook.functions.match("Better", _column, 0 /*exact match*/); 
   _rowMatching.load("value"); 
   context.sync();             
   console.log(_rowMatching.value); 
   return context.sync();             
}).catch(function (error) { 
   console.log(error); 
}); 

Identifying Cell Formatting

export const officeReady: Promise<{ 
   host: Office.HostType | null; 
   platform: Office.PlatformType | null 
   }> = new Promise((resolve) => { 
  Office.onReady() => { 
     await initBoldTracker(); 
     const root = createRoot(document.getElementById("root")!); 
     root.render(<ExcelApp />); 
  }); 
}); 

const TRACK_RANGE = "A1:F20"; 
const NAME_BOLD = "propertiesBOLD"; 
const POLL_INTERVAL_MS = 2000; 

let debounceTimer: number | null = null; 
let updating = false; 
let lastBoldSnapshot = ""; 

export async function initBoldTracker() { 
  try { 
    await registerEventHandlers(); 
  } catch (e) { 
    console.warn("Could not register format/selection event handlers:", e); 
  } 
  await updateBoldNameConstant(); 
  startPolling(); 
} 

function startPolling() { 
  window.setInterval(() => { 
    updateBoldNameConstant().catch(console.error); 
  }, POLL_INTERVAL_MS); 
} 

function scheduleUpdate() { 
  if (debounceTimer) clearTimeout(debounceTimer); 
  debounceTimer = window.setTimeout(() => { 
    updateBoldNameConstant().catch(console.error); 
  }, 150); 
} 

async function registerEventHandlers() { 
  await Excel.run(async (context) => { 
    const sheet = context.workbook.worksheets.getActiveWorksheet(); 

    sheet.onSelectionChanged.add(async () => { 
      scheduleUpdate(); 
    }); 

    await context.sync(); 
  }); 
} 

async function updateBoldNameConstant() { 
  if (updating) return; 
  updating = true; 

  try { 
    await Excel.run(async (context) => { 
      const wb = context.workbook; 
      const sheet = wb.worksheets.getActiveWorksheet(); 
      const target = sheet.getRange(TRACK_RANGE); 

      target.load(["rowCount", "columnCount"]); 
      await context.sync(); 

      const cells: Excel.Range[] = []; 
      for (let r = 0; r < target.rowCount; r++) { 
        for (let c = 0; c < target.columnCount; c++) { 
          const cell = target.getCell(r, c); 
          cell.load("address"); 
          cell.format.font.load("bold"); 
          cells.push(cell); 
        } 
      } 

      await context.sync(); 

      const boldAddrs: string[] = []; 
      for (const cell of cells) { 
        if (cell.format.font.bold === true) { 
          const a1 = cell.address.split("!")[1]; 
          boldAddrs.push(a1); 
        } 
      } 

      const items = boldAddrs 
        .map((a) => `"${a.replaceAll(`"`, `""`)}"`) 
        .join(","); 

      const refersTo = items.length ? `={${items}}` : `={""}`; 

      if (refersTo === lastBoldSnapshot) return; 
      lastBoldSnapshot = refersTo; 

      // Delete existing name if present (check both workbook and sheet scope). 
      const wbName = wb.names.getItemOrNullObject(NAME_BOLD); 
      const sheetName = sheet.names.getItemOrNullObject(NAME_BOLD); 
      await context.sync(); 

      if (!wbName.isNullObject) { 
        wbName.delete(); 
        await context.sync(); 
      } 
      if (!sheetName.isNullObject) { 
        sheetName.delete(); 
        await context.sync(); 
      } 

      sheet.names.add(NAME_BOLD, refersTo); 
      await context.sync(); 
    }); 
  } finally { 
    updating = false; 
  } 
} 

Creating user defined functions

link - learn.microsoft.com/en-us/office/dev/add-ins/excel/custom-functions-overview
[[Custom Functions]]