Crypts Macro has a GO macro with a modifier that is sort of what you are looking for Crypts Unholy Hole - #100 by Feral.pumps
Elfyau also works well his is more built in to the standard rotation. Elfyau's DF v1.1 Unholy Death Knight **Updated 22-Aug-23** - #6 by Elfyau
And then there is mine, My Macro and Builds I Really Use *Updated 07/15/2023* 10.1.5 UNHOLY PVP/PVE - #39 by Enmity
with a modifier as well, or you can just put the Cool down macro onto your bar and click it as needed.
in most cases if you are starting off cold with no casts on Cool Down waiting. the Macro should fire off as intended but once one cool down is used say for example killing trash then your macro will only use the cool downs as they become available.
Another factor, is your speed of mouse clicks if it is too fast it will skip over a cast, if you find this problem, you can either use a slower MS click. Or you can add a cast of the same twice or three times to be sure it wont just skip over a cast.
Or you can put the casts you want on your bar, and click them as needed, you will still be governed by the availability of the cool down timer, available runes etc.
All of the Contributors have excellent Macros, it is just finding one that works with your play style or a bit of tweaking to do what you want them to do within reason.