not a macro, it's accomplished by binding movement in different directions to the same key across your toons.

there's a few posts about the various permutations folks use, but the gist of it is (for a cross pattern):
toonA - forward
toonb - strafe left
toonc - strafe right
toond - backward

all bound to your "spread out" key of choice. I use 'f' as my "follow main" key and ctrl-f as my spread out key. If you combine a couple different "formation" keys you can get some fairly nice results (example: one that spreads your toons out in a standard diamond, then another that shifts only a couple one way or another as needed).