Change shortcut used by VC microphone for 'activat

Is it possible to change the shortcut that is sent when you do a ‘activate microphone’?

I changed my Dragon configuration to use {ctrl}+{numpad +} which works fine, but activate microphone seems to still be sending just the {numpad +} .

It used to be possible to do this but no longer.
It's going to take a while to check into this...