Yep -

there is a wiki entry on this - i think it's under the macros section - not exactly intuitive, but it is in there.

basically think of it this way assign a single key to different things on each slave. I use the number pad for this, but you can use any key to do it.

Main - no binding
Slave 1 - Move forward - num pad 8
Slave 2 - Move backward - num pad 8
Slave 3 - Strafe left - num pad 8
Slave 4 - Strafe right - num pad 8

now when you press the 8 on the num pad your main will not move, but the slaves will each move in a different direction creating a cross or plus-sign shape.

all formations are pretty much done this way, although i only have 2 setup - a line and a wedge shape - done with 3 keys total