Perhaps the output from the NT box isn't plain old line oriented text ? The way you are reading off the socket will only work if the NT box is sending newlines.

You may want to try using read() to read bytes, instead of using the diamond operator.

Another thought is to install Win NT's lpd client (this comes with NT, install from the Network app in the Control Panel).

Once you've done that, you could configure your unix lpd daemon and create a queue that runs your script.