Thanks.
I was able to review your model, and based on your feedback decided to simply create a C model containing the processor expert, but force C++ compilation. This allowed me to encapsulate the C functions with the "#ifdef __cplusplus" extern "C" flag along with the C++ files I needed to import into the project. So far, the forced C++ compilation seems to have worked, and I'm able to see output at the 115K baud rate that I needed to prove the concept. My next step is to generate and import the C++ files.