DK macro needed.

I'm sorry to say but you can't do that anymore, that was possible in the very early days of WoW, but we thought it made macros too powerful and removed that kind of functionality. In general I think that "automatized" gameplay is usually almost never fun, it's simply easier.

What you can do though is get some good addons that show in a very clear way what procs are up at any given moment in a way where you simply can't miss the ones that matter the most for your rotation. There’s quite a few out there that fit the job and I’m sure some players will give you their personal recommendations.