Best Way to Pipe Data Contents into Array Related Arithmetic Functions

I’ve noticed two general formulas for IO’ing string defined variables into arithmetic related array formulas that tend to only work according to specific needs. The following works in very basic array number list related cases:

let Stdin = “9; 11; 3; 4; 5; 6; 7; 8”
let str = [|Stdin|]

But it won’t work with more complex System.Int32 value related functions eg. System.Int32.MinValue or System.Int32.MaxValue. Number lists don’t read uncorrupted. This will work with complicated F# math functions:

let Stdin = [1;2;3;4;5;6]
let str = match Stdin with | 1::tail → tail

Adding get head/tail component for the sake of keeping code small did the trick. The above function will not work similar to a combination of the first and second example such as:

let var = “1;2;3;4;5;6”
let Stdin = [|var|]
let str = match Stdin with | 1::tail → tail

or

let var = 1;2;3;4;5;6
let Stdin = [|var|]
let str = match Stdin with | 1::tail → tail

Neither of these formulas function. The second of these makes more sense to me because it regards less abstracts eg. double quotes, while the static and working array function example with the numeric list already intricated into it doesn’t call for extra language. What general formula should I use that only concerns number lists that are IO’ed into F# subroutines from other generally coded subroutines that can help to keep verbose F# subroutines relative to the last 2 examples normative?