How can I disable at application level a network interface?

The main question is this:

If I disable the nic trough wmic (win7) or devcon (XP), the "plug and play" of a wired nic doesn't work any more. For example, if the user put the cable on a disabled nic, the OS doesn't know about it.

So I need to persist the enable condition but disabling the networking like a disable nic.

There's some API, network configuration (routing, changing ip, changing gateway, any), .NET Framework resource (Only NetFramework 2.0) or do you can think in any workaround to do this?

Suggest and ideas also will be treated as a solution.

Thanks and kind regards.