thats an odd set up for a macro, but for my tastes i did it differently. if you use trinity bars just set up a bar with 5 buttons and keybind them to say, F9 to f12 and shift F12 for the fifth toon. Then just set up each button for /focus toonA, /Focus toonB, etc

make these your master focus controlls! i've even got it set up so that if i focus a new toon, it PiP swaps in keyclone, brings the new focus to the main screen and resets keybinds so that my auto run key and move forward key swaps to the "main control" setup ie alts have no autorun key and SHIFT "W" to move forward, main has mousebutton for autorun and "W" to move. the keybind thing doesnt work mid combat but it works for the focus switch .
:thumbsup:
then i bind F to /follow focus /assist focus in one macro, (for my melee team, for casters team its just /assist focus) you just spam that key to aquire targets and go to dpsing

works like a charm, its just that you have to set up 5 - 6 different buttons for the focus control... i love it for the "on the fly" changing especially with the PiP swap*

i know this may not be exactly what you want( the idea of a one button control for this would be awesome, but for the PiP swap this be the best way to do it! )

good luck