Here's a quick rundown on the differences between move, domove and commandmove.
Move: This will give the whole group movement orders, effectively setting a new waypoint for the group (in fact that's exactly what it does).
Commandmove: This will give a single unit an order to move to a position. The leader of the unit's group will issue the order, eg. "2 GO TO 21 7"
DoMove: This is the silent form of commandmove. It is exactly the same command, except the unit's leader won't give the order.
in your script or trigger which ever you're using type
[unit1,unit2,unit3] commandmove getpos positiontomove
unit1 and 2 and 3 are the names of the units you want to move.
positiontomove can for example be a name of a game logic which you have placed there where you want the units to move to.