Confused over location of coroute files for 737NGX

I have both a 747 X and recently 737NGX. When I installed the NGX it created a folder PMDG/FLIGHTPLANS/NGX. I had some 747X flight plans in the original FLIGHTPLANS folder.

However when I export routes say from PFPX or Vroute intending them for the 737NGX,they come out in the format .rte and wind up in the FLIGHTPLANS folder not the PMDG/FLIGHTPLANS/NGX folder. When I press the coroute button in the FMC with the 737NGX it seems to find them and list them just fine, ie it does not seem to look in the PMDG/FLIGHTPLANS/NGX folder rather the PMDG/FLIGHTPLANS folder

For future reference when I export 737NGX flight plans what is the proper folder to point them to? Does it matter if they are mixed in with those for the 747X? The 747x seems to be able to load .rte files just fine [ie a route seems to work equally well for 747X as 737NGX without having the .rt2 extension] , but clicking on the coroute in the 747X does not bring up a list of routes like it does with the 737NGX. Is that a feature issue or perhaps the 747X does not look in the right placed or cannot sort .rte files to display them and is looking for .rt2 files.

Thanks

Greg