C#生成随机验证码

要求：要求返回一个验证码，并且不能同时存在容易混淆的0和Q；每个字母取得的概率要相同。

private static string CreateCode(int count)
        {
            string code = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z";
            string[] keyCode = code.Split(',');
            string validateCode = string.Empty;
            Random rand = new Random();
            do
            {
                validateCode = string.Empty;
                for (int i = 0; i < count; i++)
                {
                    string s = keyCode[rand.Next(0, 35)];
                    validateCode += s;
                }
            }
            while ((validateCode.Contains("0") && validateCode.Contains("O")));
            return validateCode;
        }