Your best bet is to add the code to a C++ project in Visual Studio, hit compile, and then work out the bugs that pop up. On the other hand, converting from C++ to C# is not a trivial task as they are completely different languages and rely on completely different libraries.
You do have a possible third choice, which is to compile your Turbo C++ into a DLL, then call the needed functions from C# via
PInvoke[
^].