TCL over RDP is technically barely possible with a ridiculously custom client and a server-side stub:
https://rdp2tcp.sourceforge.net/
I used it for signalling phone calls from the client to an RDP RemoteApp and initiating calls from the RemoteApp.
I would decline that project if I was asked today.
TCL over RDP is technically barely possible with a ridiculously custom client and a server-side stub:
https://rdp2tcp.sourceforge.net/