ha! i was using this in my map that i just completed today.
first, you make your pillar. if you want it to scoot over, tie it to a "func_door". if you want it to fall over, use a "func_door_rotating" and make the origin at the very bottom where it will do it's pivoting, then check the flag "y-axis" (i think) in it's properties. whichever, you have to give it a name uner the Name property.
then make your block. if you want it to drop/move the pillar when blown up (like if the block was holding a tipped over pillar) then use a "func_breakable" and set it's Target as the name of your pillar, and set it's Strength to however much "hp" you want it to have. if you want a block that just stays there but moves the pillar when shot, use "button_target". if you use this, u have to tell the door to stay open by setting some property of the door to -1. just look, you can't miss it. but once again, you need to set the button's target to the name of your pillar.