In Chile there are many small towns with local airports without VOR and NDB’s, but with local radio stations, which are normally used by pilots as locators.
That information would be very valuable to use it in the FSX.
I expect that if you can set the frequency in your radiopanel, that you can navigate to it. But you'll have create some sort of add-on scenery or updated nav package with the required details for the radiostations that do not exist in FSX / P3D.
I would not start editing the default navigation database, unless you know exactly what your are doing.
But you can heck out this site:
They offer updates for Navdata and tools to edit. haven't used it yet myself.