If you explore the DAQmx Property Nodes menu, you will find the following, both methods below work.

The .nce file export from MAX shows you the information hidden inside the Task:
[DAQmxChannel DI_InsideWin1/DigitalIn]
DI.InvertLines = 0
ChanType = Digital Input
PhysicalChanName = Dev3/port1/line0
Once you see this, it's clear that you need to access the Property PhysicalChanName.