Disable toolbar button until the button-script is done

I have this button on my toolbar to restart my 3G router:

@runmode:min
@confirm:Calls and connectivity will be interrupted.|Reboot|Cancel
@sync:"reboot_huawei.py"
@confirm:Reboot complete|OK

(the external Python script reboots the router and pings it every second until it responds again, that's how it knows it's done rebooting and after that the script terminates, this usually takes around 10 seconds)

It would be really neat if I could have the button disabled when triggered, and re-enabled automatically after the button script ends (successfully or not). Some kind of new @ modifier would be ideal for this.