What are you trying to do exactly? I'm thinking it might be tremendously easier to do with something other than piping a .txt into a .bat.

It is sometimes useful to know the network commands to analyze or configure your TCP/IP networks. Here is the list of commands that can be used in the command prompt. This command is also useful to ...

The network adapter you're trying to change the IP for named "local area connection". It could also be named as "local area connection 2" or "wireless network connection". Look in your control panel ...

I would think one of dynamic DNS client utilities might do this... Check through the list here and see if any allow running an external command on detection ...