RAM Concept V8i Slab edge thickening and slab thickness.

I am currently designing a 40mx20m ground bearing slab/raft foundation and would like to know if it is possible to model thickening at the edges as the slab will be supporting line loads due to masonry and point loads due to the steel superstructure at the edges. Furthermore, the slab is currently envisaged to be 500mm deep on one side and 300mm deep on the other side, due to much heavier loading on the 500mm side. Is it possible to model this?

Thanks,

Laurence