C++ routine from New Era

I need to call a C++ routine from a New Era handler and pass in a filename (char(10)). Reading the "documentation" indicates a need for some very fuzzy stuff to do this. If I want to call an .exe called DOIT and pass in FILENAME : call DOIT(filename) What needs to be in the C++ code (above and beyond the regular C++ code) to take that? Anything special or am I overcomplicating? Thanks....MJ