First make a command somewhat like this

<<Catoshock>>
macro /cast [target=focus,exists,nodead] Polymorph
<<Catoboom>>
macro /cast [target=focus,exists,nodead] Entangling Roots
<<Catoshadow>>
macro /cast [target=focus,exists,nodead] Shackle Undead

The CC wizard will create this if your using all the same cc spell otherwise just run the wizard then edit the command it creates.

You can now select a target and use the "Targ->BlockB"(default bound to Numpad 2, this is a prompted command so it will ask you to select a character just press the number of that characters channel) command to set the target to the appropriate focus.

Then just run your CC(default bound to f5) command and whoever has a focus will CC it.

Note:
If your using shamman's Hex ability their is a WoW bug with casting on a focus. To fix this use the following code for shamman:

<<ShamanName>>
Macro /target focus 
macro /cast [target=target,exists,nodead] Hex
Macro /targetlasttarget