nexus-prince shaffar attack script help.

/cast [target=ethereal beacon,harm,nodead,exists] [target=Nexus-Prince Shaffar,harm,nodead,exists] lightning bolt
/castrandom [target=ethereal beacon,harm,nodead,exists] [target=Nexus-Prince Shaffar,harm,nodead,exists] chain lightning

need something like this in the same macro that will allow me to target the beacon and cast chain light and if its on cooldown cast regular lightning bolt to take out the beacons and if they are dead then target shaffar.

can anybody help me with this macro?

4 shamans 1 pally