As I know in SAP2000 10 is up to now no possilbility to display distance , and pick distance of the two points (nodes) is also not aviable may be in realese 11. You can export the view to some CAD system make the dimension an prepare picture for SAP document complicated but possible STAAD...
Solution of the problems is in 3D object in AutoCad space, When you draw the cube an after that create dxf file (ASCII) SAP2000 V10 is able to read it as solid element. You have also posilbilty to draw many object each layer coud represent som structural elemnet (FRAMES, shells, etc.) in SAP...