Script to create / rename a sheet

hey i found the following script to make a copy of the active spread sheet, and rename it
This is for google drive

function CreateNewTimesheet() {

// The code below makes a duplicate of the active sheet
var ss = SpreadsheetApp.getActiveSpreadsheet()
SpreadsheetApp.getActiveSpreadsheet().duplicateActiveSheet();

// The code below will rename the active sheet value of cell c5
var myValue = SpreadsheetApp.getActiveSheet( ).getRange("C5").getValue();
SpreadsheetApp.getActiveSpreadsheet().renameActiveSheet(myValue);

how can i make it make a copy of a sheet name as apose to the active sheet, for example i got 4 sheets, sheet1, sheet2, sheet3,sheet4 and i want it to make a copy of sheet3 not the active sheet, then rename that sheet to sheet2 cell C1 value.

Thanks for any help.