// Source directory path.
U16String srcDir("SourceDirectory\\Excel\\");

// Output directory path.
U16String outDir("OutputDirectory\\");

// Load the input Excel file
Workbook workbook(srcDir + u"Sample1.xlsx");

// Get the first worksheet
Worksheet worksheet = workbook.GetWorksheets().Get(0);

// Copy Row
worksheet.GetCells().CopyColumns(worksheet.GetCells(), 0, 6, 3);

// Save the Excel file
workbook.Save(outDir + u"CopyColumns_out.xlsx");