While KM doesn't fully support array variables, any variable with delimeters is sort of an array: You can reference an item in a position. So given the variable myTest with contents a,b,c, then...
%Variable%myTest% = a, ... = b, and ... = c
The problem is you can only refer to these specific positions to read their values; you cannot write to a specific position—you can only write the full variable. So while these semi-arrays are great for storing lots of information in one spot, they're not so good if you want to update that information.
But there's actually a relatively simple way to do it, at least for small relatively static arrays. Given the same example from above, if I want to change a,b,c to a,foobar,c I can do so like this:
Set Variable myTest to text:
This seems obvious in hindsight, but I searched the forums and didn't find anything similar, and it took me a few minutes to reason through ... so I thought it might be useful for others. I wouldn't want to use this method for a 20-element array that's full of often-changing dynamic data, but for small occasional-use arrays, it works great.