XLSX redigeren Formaten in C#

Workbook wb = new Workbook("e:\test2\Input.xlsx");
Worksheet sheet = wb.Worksheets[0];
FindOptions opts = new FindOptions();
opts.LookInType = LookInType.Values;
opts.LookAtType = LookAtType.Contains;
opts.RegexKey = true;
Aspose.Cells.Cell cell = null;
do
{   //find only whole word and not part of any word.  
    cell = sheet.Cells.Find("\bKIM\b", cell, opts);
    if (cell != null)
    {
        string celltext = cell.Value.ToString();
        celltext = celltext.Replace("KIM", "^^^^^^^^^^");
        cell.PutValue(celltext);
    }
}
while (cell != null);

wb.Save("e:\test2\out1.xlsx");

// Find/Replace in whole workbook.

Workbook wb = new Workbook("e:\test2\Input.xlsx");
wb.Replace("\bKIM\b", "^^^^^^^^", new ReplaceOptions() { RegexKey = true });  
wb.Save("e:\test2\output.xlsx");