Edit your post processor file (*.GPP) to multiply by -1 and to devide the result by two. I can't recall without looking if SolidCAM has a setting in the MAC file for outputting Radius values or not; if so then things are a lot easier.
Who configured the post for your machine? If it was your reseller, then get on to them. If not start reading up the help files for "GPP Tool" as this is where the post stuff is kept.