Did you try the solutions given in this thread?
At least I see one which exists for OS2006

Hi;

I too really need telnet (i have ssh, thanks fully understand all the issues) Still need telnet. Have really looked, can't even get close .
Netcat will not suffice.

Any help greatly appreciated. Have n810.

Thanks,

Steve

I found a copy of putty's plink ssh and telnet application compiled for the n8x0, it might work. I don't know how well it supports more advanced terminal functions, but so far it is working for me.

http://home.mminternet.com/~delaroca/