I am really confused here. I have written a snippet of code in C# that is passed a possible file pathway. If it contains a character specified in a regex string, it should return false. However, the regex function Match refuses to find anything matching (I even set it to a singular character I knew was in the string), resulting in severe irritation from me.
The code is:

```
static bool letterTest(string pathway)
{
    bool validPath = false;
    char[] c = Path.GetInvalidPathChars();
    string test = new string(c);
    string regex = "["+test+"]";
    string spTest = "^[~#%&*\\{}+<>/\"|]";

    Match match = Regex.Match(pathway, spTest);

    if (!match.Success)
    {
        validPath = true;
    }

    return validPath;
}

```

The string I pass to it is: `@"C:/testing/invalid#symbol"`

What am I doing wrong/misunderstanding with the regex, or is it something other than the regex that I have messed up?