I'd heat the milk, sugar and flavourings etc for about 6-8 minutes first, at 100 speed 1.Then add the rice and cook until it's cooked.
About 30 minutes at 90 on reverse. Make sure the mixture is turning - you may need speed 1 or 2 for this.
I would add the strawberries at the very end and just blend them in on reverse, or even better add them by hand.