Hi William, welcome to the forum!
No, this is not working/supported currently. We have an open feature request on this that I have linked your thread to so that I can track the status of that. If there's any updates on the status of that feature request, I will let you know.
Let me clarify one point, based on the code snippet you gave.
The Intel C++ Compiler does not support /clr or the managed runtimes, so "for each" syntax in that context would require an entirely different feature request. The report I referenced is in regards to "for each" syntax being applied to C++ STL containers in native compilations.
The Intel(R) C++ Compiler supports for,each,in syntax now with version 15.0 (available in Intel(R) Parallel Studio XE 2015, all editions). Let me know if you need anything else.