You van execute a process on an other machine from C#, by using the code below:

Example for calling the function

var rc = new RemotingComponent(null);
rc.RunRemoteProcess
(
    @"MyMachine1", 
    "MyMachine1\Administrator", 
    "MyPassword1", 
    @"C:\Windows\System32\notepad.exe",
    string.Empty
 );

C# class

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Management.Automation;
using System.Management.Automation.Runspaces;
using System.Security;
using System.Text;

namespace Research
{
    public interface IRemotingComponent
    {
        void RunRemoteProcess(string machineName, string userName, string password, string processPath, string processArguments);
    }

    public class RemotingComponent : IRemotingComponent
    {
        public void RunRemoteProcess(string machineName, string userName, string password, string processPath, string processArguments)
        {
            var connectTo = new Uri(String.Format("http://{0}:5985/wsman", machineName));

            _logger.Info("Building powershell command.");
            var command = new StringBuilder();
            command.AppendLine("$pinfo = New-Object System.Diagnostics.ProcessStartInfo");
            command.AppendLine(string.Format(@"$pinfo.FileName = ""{0}""", processPath));
            command.AppendLine("$pinfo.UseShellExecute = $false");
            command.AppendLine("$pinfo.RedirectStandardError = $true");
            command.AppendLine("$pinfo.RedirectStandardOutput = $true");
            command.AppendLine("$pinfo.CreateNoWindow = $true");
            command.AppendLine(string.Format(@"$pinfo.WorkingDirectory = ""{0}""", new FileInfo(processPath).Directory.FullName));
            command.AppendLine(string.Format(@"$pinfo.Arguments = ""{0}""", processArguments));
            command.AppendLine("$p = New-Object System.Diagnostics.Process");
            command.AppendLine("$p.StartInfo = $pinfo");
            command.AppendLine("$p.Start() | Out-Null");
            command.AppendLine("$output = $p.StandardOutput.ReadToEnd()");
            command.AppendLine("$p.WaitForExit()");
            command.AppendLine("$output");
            
            string shell = @"http://schemas.microsoft.com/powershell/Microsoft.PowerShell";
            using (var passing = new SecureString())
            {
                foreach (char c in password.ToCharArray())
                {
                    passing.AppendChar(c);
                }
                passing.MakeReadOnly();
                var credentials = new PSCredential(userName, passing);

                var connection = new WSManConnectionInfo(connectTo, shell, credentials);
                using (var runspace = RunspaceFactory.CreateRunspace(connection))
                {
                    runspace.Open();

                    using (var powershell = PowerShell.Create())
                    {
                        powershell.Runspace = runspace;
                        powershell.AddScript(command.ToString());

                        var results = powershell.Invoke();
                        runspace.Close();

                        foreach (var obj in results.Where(o => o != null))
                        {
                            Console.Writeline(string.Format("Output: [{0}].", obj));
                        }
                    }
                }
            }
        }
    }
}