WIntablet>Nano convert serial to I2C >add comport to existing I2C keyboard

I have an idea, it's preliminary, and I could be wrong about any of it:
I have all the following parts (and more).

I want to add a Ublox Neo6m internally/permanantly to an RCA Cambio Atom Win10 tablet.
There is a free comport available in devmgr, but I can't find attachment points on the mobo for that com port to hook the serial gps into. The tablet only has 1 external usb port, and I don't want to tie it up with the gps. I might be able to find other usb on the mobo, but I haven't looked for *that yet.

I want to use an Arduino Nano Pro to convert the GPS serial data to an I2C connection , and know if I can piggyback it on the internal keyboard connector (I believe the keyboard is I2C, but I'm not sure) (or some other I2C device on the mobo). Assuming that the keyboard (or other) is an I2C connection, and I can piggyback the Nano Pro, how do I install the new I2C device (nano pro) as a comport in devmgr? I know this is more of a hardware/windows question than an arduino question, but I thought you all would have the best chance of knowing if it were possible/how to.