/castsequence reset=24 Curse of Agony, Corruption, Immolate
that should cover it for you. though you might want to adjust the reset timer. basically it means that if you don't press the macro during that time (in seconds) then it'll reset back to the first spell on the list, so 5-10 seconds is probably more appropriate. also it'll reset to CoA if you press it 3 times as these sequences just loop if you spam them.
a nice little macro you might want is:
/castsequence [nomodifier, target=player] reset=N Fel Armor, Detect Invisibility, Unending Breath
/castsequence reset=N [modifier:ctrl] Detect Invisibility, Unending Breath
/castsequence reset=N [modifier:shift] Find Herbs, Sense Demons
/cast [modifier:alt] Demon Armor
i THINK the shorthand for /castsequence is /cs but tbh, i haven't tried.. though i should as i need to neaten up my macros...
Edited, Jan 18th 2008 3:43am by Jenovaomega