How to enable Android tethering via shell command(s)?

Is there a way to enable the USB Tethering option in Android 2.2 FRG22D using a shell command?

My goal is turn a Motorola Droid running Android 2.2 into a micro server. This device cannot connect to 3G and Wifi is not option. The device will always be connected via USB to a computer with a network connection. I have gotten the reverse tethering working, but I still have to manually check the USB Tethering check box (Settings->Wireless & Networks -> Tethering -> USB Tethering) every time the USB connection resets (such as when the computer is rebooted, the cable is unplugged, etc). My goal is write a script that can be ran on the host computer to bring the USB Tethering up without having to touch the Droid (I have root access开发者_StackOverflow社区 and the device will always be connected via USB so I can issue shell commands using ADB).

I have been searching for a shell command to do this but nothing has turned up. Another possible solution is that I could write a small app (either using the NDK or SDK) and call that from the script, but again I cannot find any information on how to change system settings (at least network level settings) via code.

Any suggestions?

---

in the source code of Settings app, mWifiManager.setWifiApEnabled(null, enable) is used, but this functionality seems to be missing in the SDK (checked 2.2 and 2.3).