How to copy an excel file and save as new excel file in C# MS excel interop

How to copy, Edit ,save an excel file in a specific Location in C# using excel interop? i have following method which will edit the existing same excel.But i want to copy the original excel file and edit 2 colums and save that as a diffrent location with any name.

so i should have the original one and new one with edited.Please suggest an efficient way

My code which will edit the existing one and save as itself below.only  2 column values i have to edit

private void EditExcel(string fileName)
{
  
        Excel.Application xlApp = new Excel.Application();
        Excel.Workbook xlWorkbook = xlApp.Workbooks.Open(fileName);
        Excel._Worksheet xlWorksheet = xlWorkbook.Sheets[1]; // excel sheet 
        Excel.Range xlRange = xlWorksheet.UsedRange;
   
        int lastUsedRow = xlWorksheet.Cells.Find("*", System.Reflection.Missing.Value,
                           System.Reflection.Missing.Value, System.Reflection.Missing.Value,
                           Excel.XlSearchOrder.xlByRows, Excel.XlSearchDirection.xlPrevious,
                           false, System.Reflection.Missing.Value, System.Reflection.Missing.Value).Row;

   
           
            for (int i = 2; i <= lastUsedRow; i++)
            {
                int j = 0 + i;

                xlWorksheet.Cells[i, 1] = "new value";
                xlWorksheet.Cells[i, 2] = "new value";
                xlWorksheet.Cells[i, 3] = xlWorksheet.Cells[i, 3]
             
            }

            //cleanup  
            GC.Collect();
            GC.WaitForPendingFinalizers();

            //release com objects to fully kill excel process from running in the background  
            Marshal.ReleaseComObject(xlRange);
            Marshal.ReleaseComObject(xlWorksheet);

            //close and release  
            xlWorkbook.Close();
            Marshal.ReleaseComObject(xlWorkbook);

            //quit and release  
            xlApp.Quit();
            Marshal.ReleaseComObject(xlApp);

        }