Run command line code programmatically using C#

try this

ExecuteCommand("Your command here");

call it using process

 public void ExecuteCommand(string Command)
    {
        ProcessStartInfo ProcessInfo;
        Process Process;

        ProcessInfo = new ProcessStartInfo("cmd.exe", "/K " + Command);
        ProcessInfo.CreateNoWindow = true;
        ProcessInfo.UseShellExecute = true;

        Process = Process.Start(ProcessInfo);
    }

You may use the Process.Start method:

Process.Start(
    @"C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis.exe",
    @"-pdf ""connection Strings"" ""C:\Users\XXX\Desktop\connection string\DNN"""
);

or if you want more control over the shell and be able to capture for example the standard output and error you could use the overload taking a ProcessStartInfo:

var psi = new ProcessStartInfo(@"C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis.exe")
{
    Arguments = @"-pdf ""connection Strings"" ""C:\Users\XXX\Desktop\connection string\DNN""",
    UseShellExecute = false,
    CreateNoWindow = true
};
Process.Start(psi);

You should be able to do that using a process

        var proc = new Process();
        proc.StartInfo.FileName = @"C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis.exe ";
        proc.StartInfo.Arguments = string.Format(@"{0} ""{1}""" ""{2}""","-pdf","connection Strings" ,"C:\Users\XXX\Desktop\connection string\DNN");
        proc.StartInfo.UseShellExecute = false;
        proc.StartInfo.RedirectStandardOutput = true;
        proc.Start();
        string outPut = proc.StandardOutput.ReadToEnd();

        proc.WaitForExit();
        var exitCode = proc.ExitCode;
        proc.Close();