I'm not sure how familiar you are with telnet but htere is a lot of control code that is sent by the client to the server that has nothing to do with the commands. You can't just send commands without the control code. You should either read the telnet IRFC or try to find a telnet API for VB which would simplify a telnet session.
But I think you just want to call the telnet program and inject commands into it, rite? I'm not really too sure about that since I mostly work with Perl, which would be the perfect language for this.
I KNOW EVERYTHING. ASK ME.