I dare say it was actually me who posted that on the general forum!

Quote Originally Posted by Steph
I use WASD & co to move the primary account's character. I removed these mappings from the secondary systems. I use the arrow keys to move the secondary characters and removed the bindings for them on the primary pc.

I also have two keys to scatter and unscatter the group. I use numpad 0 and period for that. Num0 is bound on secondary 1 to forward, on seconday 2 to backward, on 3 strafe right on 4 strafe left. That makes my chars step neatly apart as seen in the video. The corresponding opposed movement directions are bound to the second key.
http://www.dual-boxing.com/forums2/viewtopic.php?t=31

It works really neat.