Here is an alias I wrote to create a clipping ‘box’. I assigned it to a ‘CB’ alias. It creates 6 clipping planes as a group around the point you pick. It can be enlarged or shrunk on any axis with the gumball grips. Yes, the script can be copied into an alias even as large as it is.
'_Cplane PAUSE setredrawoff clippingplane p -.5,-.5,10 .5,-.5,10 -.5,.5,10 sellast group ENTER setgroupname cb clippingplane p .5,-.5,-10 -.5,-.5,-10 .5,.5,-10 sellast group enter setgroupname cb clippingplane p -10,-.5,-.5 -10,-.5,.5 -10,.5,-.5 sellast group enter setgroupname cb clippingplane p 10,-.5,.5 10,-.5,-.5 10,.5,.5 sellast group enter setgroupname cb clippingplane p .5,-10,.5 -.5,-10,.5 .5,-10,-.5 sellast group enter setgroupname cb clippingplane p -.5,10,.5 .5,10,.5 -.5,10,-.5 sellast group enter setgroupname cb selnone setredrawon