This is 2 separate Macros to set a focus and then to CC your Focus Target. This allows you to not have to change targets every time you need to reapply your CC. This could be modified for off-tank healing and such, if you come up with one just reply on this thread.
Macro 1 (to set focus target)
/focus
Macro 2 (spell, fear for this example)
/cast [target=focus] fear
Macro 1 (to set focus target)
/focus
Macro 2 (spell, fear for this example)
/cast [target=focus] fear