custom cmdlet entry in remote powershell

Question

I have been trying for days to add my custom cmdlet to the runspace of a remote powershell in C#

string shellUri = "http://schemas.microsoft.com/powershell/Microsoft.PowerShell";
        System.Security.SecureString sString = new System.Security.SecureString();
        foreach(char passwordChar in password.ToCharArray())
        {
            sString.AppendChar(passwordChar);
        }
        PSCredential credential = new PSCredential(username, sString);
        WSManConnectionInfo connectionInfo = new WSManConnectionInfo(false, computerName, 5985, "/wsman", shellUri, credential);
        try {
            using (Runspace runspace = RunspaceFactory.CreateRunspace(connectionInfo))
            {
                runspace.Open();
                pipe = runspace.CreatePipeline();
                pipe.Commands.AddScript(script);
                    Collection<PSObject> result = pipe.Invoke();
                    foreach (PSObject line in result)
                    {
                        scriptOutput.Add(line.ToString());
                    }
                pipe.Dispose();
                runspace.Close();
            }

I have something like this that works to execute script on a remote machine. But I need to add a custom cmdlet.

I know with a local powershell you can use InitialSessionState like this :

InitialSessionState iss = InitialSessionState.CreateDefault();
        SessionStateCmdletEntry gfv = new SessionStateCmdletEntry("Get-Custom", typeof(GetCustomCommand), null);
        iss.Commands.Add(gfv);
        using (Runspace runspace = RunspaceFactory.CreateRunspace(iss))

Where GetCustomCommand extends PSCmdlet.

But with remote powershell you can't initialize the runspace with InitialSessionState. How can I add an SessionStateCmdLetEntry to my remote runspace ?

Could someone help me ? Thanks