void Main()
{
	var list = new List<string>() {
		"AB1235",
		"AB9999",
		"AB99",
		"AB999",
		"AB12",
		"AB123",
		"14",
		"12",
		"123",
	};
	var ordered = list.OrderBy(l => PrependDigits(l));
	foreach(var item in ordered)
		Console.WriteLine(item);
}

public static Regex regexPrependDigits = new Regex(@"\d+", RegexOptions.Compiled);
public static string PrependDigits(string s) 
{
    if (string.IsNullOrWhiteSpace(s))
        return s;
    return regexPrependDigits.Replace(s, m => m.Value.PadLeft(10, '0'));
}

Output:

12
14
123
AB12
AB99
AB123
AB999
AB1235
AB9999

Typescript prependdigits version

function prependDigits(s: string, len: number = 10): string
{
    return String(s).replace(/\d+/, (m) => m.padStart(len, "0"))
}

335200cookie-checkC# simple natural sort (with max digits)no