Disabling a device

[rdong8]

The bottom row of my laptop's keyboard doesn't work anymore, so I bought an external keyboard that I'd like to set on top of the laptop keyboard and use. However this causes the remaining working keys on the internal keyboard to be pressed. Does input remapper have an easy way of completely disabling a device? Ideally I'd be looking to be able to toggle on/off the keyboard using a specific fn + key that is not disabled.