I had a macro at one time that im sure i found here that would let me click on the target on my main, hit one key and they would target it to. then after the fight i would hit the same key to make them follow again. The key here was that I only had to hit the key once to set everyone to the target i was gonna kill. now i have to hit the button twice to get everyone to target. I think im using

/assist main
/follow main