Ввести строку и заменить все числа на знак "*"

#include "stdafx.h"
 
using namespace System;
 
int main(array<System::String ^> ^args)
{
    Console::WriteLine("Ввести строку:");
    String ^s = Console::ReadLine();
    for (int i = 0; i < s->Length; i++)
        if (s[i] == '1' || s[i] == '2' || s[i] == '3' || s[i] == '3' || s[i] == '5' || s[i] == '6' || s[i] == '7' || s[i] == '8' || s[i] == '9' || s[i] == '0')
        {
        ????
        }
    Console::WriteLine("\nРезультат:\n" + s);
    Console::ReadLine();
    return 0;
}

String^ tmp = "";
for (int i = 0; i < s->Length; i++)
{
    if (s[i] == '1' || s[i] == '2' || s[i] == '3' || s[i] == '4' || s[i] == '5' || s[i] == '6' || s[i] == '7' || s[i] == '8' || s[i] == '9' || s[i] == '0')
    {
        tmp += "*";
    }
    else
    {
        tmp += s[i];
    }
}
s = tmp;

using namespace System::Text;
...
StringBuilder^ tmp = gcnew StringBuilder(s);
for (int i = 0; i < s->Length; i++)
{
    if (s[i] == '1' || s[i] == '2' || s[i] == '3' || s[i] == '4' || s[i] == '5' || s[i] == '6' || s[i] == '7' || s[i] == '8' || s[i] == '9' || s[i] == '0')
    {
        tmp[i] = '*';
    }
}
s = tmp->ToString();

using namespace System::Text::RegularExpressions;
...
s = Regex::Replace(s, "\\d", "*");