GPS Route Planning and xfer .gps to GPS?

[IdahoRenegade]

I currently do the vast majority of my GPS route planning for extended trips on my notebook, using Garmin Basecamp.  I then transfer routes to my GPS (Oregon 450).  Is there a similar app that allows me to do so on the Nexus?  I realize the Nexus has a built in GPS, but don't want to use it much of the time.  I ride motorcycles in the backcountry and would rather keep the Nexus packed away safe until I'm stopped, using the Garmin on the move.