You can copy scenarios easily in the Navigator view.
To copy a scenario:
In the Navigator view, right click the scenario that you want to copy and select Copy from the pop-up menu.
Right click the Simulation Scenarios folder scenario and select Paste from the pop-up menu.
Type a new file name and click OK.
You can copy several scenarios at once. Hold down the <Shift> key or <Ctrl> key while selecting all scenarios to be copied, and - for each scenario - enter a new name.