Hi deeloc!
The NI-CAN BusMonitor is a Windows application that runs on a CAN port
of a local NI CAN card (local in this case means 'on the same Windows
system'). Thus, you cannot run the BusMonitor on Windows and read CAN data
from a remote (RT) CAN port.
You would need to create a LabVIEW Real-Time application that runs on
your RT PXI system. That application could have a front panel on your
Windows host.
A starting point for an application like that could be the CAN Receive.vi example.
-B2k