I am using this code to check if a drawing has Z>0.
(if (and (/= (caddr (getvar "EXTMAX")) -1E+20)
(or (> (abs (caddr (getvar "EXTMIN"))) 0)
(> (abs (caddr (getvar "EXTMAX"))) 0)))
(alert "Drawing is 3D !"))
How I can get in addition, in an alert window or in command line, a list with all blocks containing objects with Z>0?