First try

Cargo.lock

@@ -0,0 +1,25 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "autocfg"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
+
+[[package]]
+name = "substring"
+version = "1.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "42ee6433ecef213b2e72f587ef64a2f5943e7cd16fbd82dbe8bc07486c534c86"
+dependencies = [
+ "autocfg",
+]
+
+[[package]]
+name = "winlink-password"
+version = "0.1.0"
+dependencies = [
+ "substring",
+]

Cargo.toml

@@ -4,3 +4,4 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+substring = "1.4.5"

src/main.rs

@@ -1,3 +1,13 @@
+use substring::Substring;
+
 fn main() {
-    println!("Hello, world!");
+    let password = "abcdefghijklmnopqrstuvwxyz";
+
+    println!("Password: {}", password_decode(&password, 3));
+}
+
+fn password_decode(password: &str, code: i32) -> String
+{
+    let decode_password = password.substring(code.try_into().unwrap(), 2);
+    return decode_password.to_string(); 
 }