Find an cell value of Excel sheet using C#?

In order to retrieve a specific cell element of Excel sheet you need to:

1. get the WorksheetPart of the required worksheet, e.g.:
Workbook workBook = spreadSheet.WorkbookPart.Workbook;
WorksheetPart worksheetPart = workBook.WorkbookPart.WorksheetParts[0];

2. locate its SheetData element, e.g.:
SheetData sheetData = worksheetPart.Worksheet.GetFirstChild();

3. locate the required Row from SheetData, e.g.:
Row row = sheetData.Elements[0];

4. locate the required Cell from Row, e.g.:
Cell cell = row.Elements[0];

Now in order to bold it you would need to manipulate with WorkbookStylesPart, for example see here. Also the above approach retrieves a specific cell based on its row and column index, but in case you want to find a specific cell that contains some text value then you would have to get SharedStringTablePart and search through its SharedStringItem in order to locate the required text and its cell reference.

All in all you must have realized by now that OpenXML SDK has some learning curve and it requires from you a knowledge of Office Open XML format.
So as a workaround I would advise you to check out this C# component for Excel workbooks. I find it to be much more intuitive, it can straightforwardly read excel files in C#, here is how you would retrieve the required cell:

var workbook = ExcelFile.Load("Sample.xlsx");
var worksheet = workbook.Worksheets[0];
 
var cell = worksheet.Cells["A1"];

Also in case you are looking for some specific text you would just use a "worksheet.Cells.FindText(...)" method. Also to bold this cell you just need:

cell.Style.Font.Weight = ExcelFont.BoldWeight;

Hello,

Following is my solution to find a number from Excel and set it as bold and I use a .NET Excel component.

            Workbook workbook = new Workbook();
            workbook.LoadFromFile("test.xlsx", ExcelVersion.Version2010);

            //find and highlight excel data
            Worksheet sheet = workbook.Worksheets[0];
            foreach (CellRange range in sheet.FindAllNumber(3501, true))
            {
                range.Style.Font.IsBold = true;
            }

Hope that my solution will be helpful for you!