Cfront was a commercial product and seems to have been discontinued. v1.0 and v3.0 are available at http://www.softwarepreservation.org/projects/c_plus_plus/index.html#cfront
If your code is old enough ( 1980s and early 1990s ) Cfront may be able to handle some of the translation, if you need to translate modern C++ code then this is probably not the right tool.
The EDG translator may be prohibitively expensive.
The comeaucomputing compiler is $50 and may not have the functionality you need.
These are worth researching but in the end you may have to use LLVM or translate the code manually and use gcc g++ or plan G.