There isn't currently a program that can covert schematics into commands, however you can use this mcedit filter http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-tools/2274235-gentlegiantjgcs-mcedit-filters on a structure you import ingame to make a command. There are limits to this filter, the greater the complexity the more command blocks it will take, however if you are using simple blocks without alot of extra nbt info, command blocks with commands in them have ALOT of extra nbt information, then you can spawn in some pretty good sized structures
I would say you shoud use minecartcommanblocks in stead of falling sand. I have been messing around with this and falling sand always glitches for me. There is a link down below as an example. Just take one of the one command creations.