We don't currently have a way of exporting Northing/Easting points to a CSV, but only for a very short period of time now. We just recently met on this, and it has a ribbon button and a plan to be added to the software in the next couple of months.
As for Units, yes, that's probably the biggest issue. AutoCAD deals in flat plane coordinate systems, as opposed to GPS coordinates. So interfacing with a handheld GPS unit would require translating from a known plane geometry, most likely utilizing software that came with the GPS unit. So we'll need to hear from a user such as yourself how to solve that riddle. What make and model GPS unit are you planning on using? Have you come across any workflows for translating coordinates between the two?
Any information you can give us about your existing methodologies would be a great help.