I understand what you are trying to do, but I can't seem to find a way to select the column without the simulator popping up a timestep error (Multisim 2001). The only way I could do it was to individually ground each column through a 330 ohm resistor and rerun the simulation for each column.
This may work in the real world, but the simulator is having difficulty with it. Maybe someone else can provide better a better solution than me. I will continue examing it to see if I can find a way to do it, but as of now I am just as baffled as you are.