using SoftArtisans.OfficeWriter.ExcelWriter;
...
ExcelTemplate oXLT = new ExcelTemplate();
oXLT.Open(Page.MapPath("Hello World.xlsx"));
DataBindingProperties oDataProps = oXLT.CreateDataBindingProperties();
string value = DataValueBox.Text.Trim();
oXLT.BindCellData(value, "DataValue", oDataProps);
oXLT.Process();
oXLT.Save(Page.Response, "Output.xlsx", false);