translate from PowerRailTrack to MX

Hello,

for a client I'm crating a bunch of rail-alignments (horizontal, vertical and cant), using PowerRailTrack V8i ss2 (08.11.07.685).
He wants to receive my designs in a usable format -GENIO is preferred, and use those alignments in MXRoads for further design of roads, paths and so forth.

I've tried the GENIO translator, but without results
I've tried the LandXML translator, that seems to work but is very picky about vertical curves (circular or parabolic). This results in a change of radius and/or length when opened in MX, and changing the project settings makes no difference..
Also, when I open the same LandXML in AutoCAD Civil all vertical curves with a negative radius (sag) have disappeared !

I have BRT, MX & Autocad Civil available, but very little experience with the latter two, so I'm running out of ideas now, any and all advice is welcome !

Greetings,
  Gerbert