I don't have this grill, but looked at the video on the Char Broil site.
If I were going to use this grill for indirect cooking, I think I'd pick up a couple of fire bricks, wrap them in foil, and keep the charcoal pan at it's lowest level. The fire bricks should block most heat that would come up directly under your meat.
But that is not based on any experience with this type of grill. Others may have better ideas.
BD