No, you can't do it. Rule of thumb for all flight tickets: you must use your flight coupons in the correct sequence. If you wish to fly in a different sequence, your ticket will be revalidated and you will be required to pay the fare difference. In your case, expect to pay a few thousand dollars, because your routing is rather uncommon and therefore will mostlikely be priced as a combination of point to point full fares. And, no full caps please, kinda "noisy." Thanks.