motor running state in NXC?

[HaWe]

my problem is similar to aswin's, but I'm using NXC not RobotC like he does.
So I think I'd better start an extra thread...
In RobotC there is a global flag which is automatically set by the firmware and which detects if motors are running (sth like running state = running or idle IIRC).

Is there such a flag available in NXC, too?