That should work.

Watch the total number of segments. If you are running out of segments: get a coupon fare (airpass) in North America. Most airline offer a certain number of coupons for a fairly good price.
Check http://www.travel-overland.de/airpass.html (in german unfortunately, click on the airline you are interested in. The table shows the number of coupons, prices at different date ranges and for adults (Erwachsene) and children (Kinder). Flights to some destinations cost more.

Also if you want to maximize miles and adding South America and Australia you can do SCL-xLAX-xHKG-SYD (for example) for a few additional miles.

Also check different starting points in Europe (there is some discussion on the board). MAD is not exactly the best point to start.