Please be more specific. What do you want to do?
Obviously, "array subset" will not allow you to insert anything into an array.
- Do you have an array of a given size and want to insert a random number to increase the array size by one? --> Use "insert into array"
- Do you have an array of fixed lenght, and want to replace one element with a new random number? --> user replace array subset.
In both cases, you can get a random number from the dice (Random number (0..1)) in the numeric palette.