How can I mask user input during telneting?

I have a socket application. The socket for connecting the client uses NetworkStream, which does not allow searching.

So, how can I mask user input when they telnet to my socket server since NetworkStream does not provide a search?

1.) It should work with third-party telnet, i.e. im without creating a telnet client 2.) I can argue that nothing is displayed in the telnet client, but I prefer to mask

Thanks in advance.