Question: I have an http proxy, which works OK, but there are some address on my lan which provides some web services.

I want to configure my device so that for some range of addresses the proxy is bypassed.

I have tried with 10.0.0.0/8, but it doesn't work!

Answer: 
This doesn't exactly answer your question, but it might help in your use case. 

Maybe you want to have a look at [InputStick](http://inputstick.com). It'll be a USB thumb drive that you pair to Android via Bluetooth. Plugged into a computer it emulates a generic USB HID to send keyboard strokes. An advanced Java API will also allow to specify i.e. device descriptors to emulate non-standard functions. It could provide a nice example that it's defined in software rather than hardware.

For reference, the developer also is working on example programs, such as a Demo Password Manager.
Have you tried [Unified Remote](http://www.unifiedremote.com/). This is a great tool to use phone as keyboard and mouse. It doesn't use USB but wifi instead. There is an app on phone and computer that work together. Works great for me. Also if you get full version you get integration with many common applications.