I would love to hear if you have experience in this area and how you accomplished this task.
I used C#. It is trivially easy to define user interfaces and to read from/write to the serial port. The only remotely challenging part is that the user interface runs one thread and serial data processing is done in another.
But, a little understanding of threads and how to communicate between threads solves that issue (which will be present in C++, too). C# threading is easy. C++ threading is not as easy.