conditional with funckey?

I have a custom key set in PCBENV:

funckey Home replay g5

When I press Home, it plays a script to change grid to 5 mils. If I'm using metric instead. I'd like to run a different script.

Is there a way to test what the units are set to?

pseudocode:

if metric

run metric script

else

run inches script

Thanks for any ideas..