There is an example in my guide.

Basically, if you have four toons, make a mapped key with four steps.
On Step 1, send the keybind to Toon A.
On Step 2, send the keybind to Toon B.
Etc.

I would set the hotkey for the mapped key, to same keybind as wherever your macro is on warcraft.

So maybe you previously pushed W for Warstomp.
If that is the case, make a mapped key, with W as the hotkey to activate it.
Have it send W to Tauren A on push 1, W to Tauren B on push 2 (step 2) etc.