There is a dfhack thread in the utilities and third party tools, in case you didn't know, and there is a readme available through a link in the first post there.
http://www.bay12forums.com/smf/index.php?topic=139553.0More directly relevant, the only way to directly move a unit that I know of which isn't broken is the gui/gm-editor but it's a kind of dangerous tool as it lets you edit the values which the game uses to tell what everything is, so you can really break stuff playing with it.
On the other hand, pos is visible right at the top of it, and you can use it to directly move something, x being left/right, y is north/south, and z is the in/out (or up/down in game) axis.
If it's at the bottom of a single tile well which we'll say is three z deep, you'd change the position by x+1 and z+3 and he'd appear at the top to the right of the well. Be careful because you can put them inside a wall so don't unpause until you are sure they are on a safe tile.
Generally the readme and thread are good places to start.
You can also put the cursor in the dfhack console (or terminal if you launch from one as I do) and type ls or ls -a to get a list of commands/plugins/scripts, then you can use ls or man plus whatever command or plugin or script you're interested in to get some useful info, and several have help files as well.