Hello,
Though you cannot route this signal to one of the eight DIO lines, you can indirectly route it to a PFI line though which will probably function just as well for you. In fact, here is a LabVIEW example that does just this.
Using the Analog Trigger Circuitry Output as an External SignalI'm not sure if you're using LabVIEW or not, but if not you should be able to get a good idea about what is going on from the description.
I hope this helps.
Russell
Applications Engineer
National Instruments
http://www.ni.com/support