Mapped Keys - cast sequence question

[death]

what im attempting to do is create a mapped key for pvp that will allow me to use obiterate > frost strike > necrotic strike > hungering Cold (4.0 delay) Frost Strike > Obliterate Hungering Cold.

tthe part where im stuck is adding the Frost Strike > Obliterate after the Hungering Cold delay as it wont progress further until after the delay
so basically trying to get it so i can use hungering cold, keep up my rotation while the delay for HC is still active, and periodically keep that going until all HC are used up.

also ive set mind freeze to a 2.5 second delay.....that also falls into the above issue, ive watched Mosg's DK manifesto, but he didnt really go into detail on how to set these up

or am i reading into this wrong, and it will only do the Mind Freeze/HC one delay and continue with the rest of the cycle?