Setting a channel to only update via command (magic sheet)

Hi everyone.

We're a school with an ETC Element in our school hall. We've got a couple of LSC Gen IV dimmers with TruPower available, which I'd like to move my LED fixtures onto (currently they're running off a few normal GPO's).

Ideally what I'd like to achieve is to have a couple of channels enabled with TruPower, say for example Channels/addresses 1 thru 4. We'd really like to have some way to turn the TruPower channels on via a button on a magic sheet (i.e an "Enable LED Fixtures" button).

I know that I could set this up fairly easily, but what I'm not sure is how to ensure that the channels/addresses can't accidentally be turned off by something like a "Go to Cue 0" command or someone turning down the GM fader.

The students create their own cues all the time, so I wasn't sure if there was a way that I could set a particular channel/address to be always on, or have it triggered via a command or similar.