Download
Anim8or and open your 3DS model with it. Go to
Options ->
Debug and check the
Dummy 3DS KData and save the model. It should be now able to be opened with Oxygen and the mappings will stay.

The texture paths wont stay though, but that's easy to fix. Just select one area on the model where you applied a certain texture, then from
Faces ->
Faces properties add the texture line there and voilá.