I'm sure others have already figured this out, but I didn't find an easy answer when I tried to do this yesterday. Here is an easy way to remove an arbitrary number of entries from the beginning of a KM string array. This macro is meant as an example for you to incorporate into larger projects.
The Search and Replace action will take an input, which in this case is hard-coded to one-two-three-four-five-six-seven-eight-nine. In reality, you would probably pass something dynamically (variable, dictionary entry, etc.)
Here is what happens based on the options you choose from the list input in this example:
n = 1 one-two-three-four-five-six-seven-eight-nine → one-two-three-four-five-six-seven-eight-nine
This example is, technically speaking, removing the first n - 1 entries, but you can customize the %Calculate%local_n - 1% part of the Regex to change that behavior.