Workbook.Worksheets[1].Range['A10', 'A10'].NumberFormat := '#,##0.00'; Workbook.Worksheets[1].Range['A1', 'A1'].EntireRow.NumberFormat := 'hh:mm:ss'; Workbook.Worksheets[1].Range['C1', 'C1'].EntireColumn.NumberFormat := '$#,##0.00_);[Red]($#,##0.00)';