We need more information.
In the simplest case, you build a GUI that builds a string, calls the terminal with that string, and then somehow communicates the result. But there's not much point, and it will always, always be hacky and easily broken. More complex cases assume that you have the source code and that it was written with this in mind-many programs are written as a library that you call and a 50-line command line frontend that calls it.
I'd suggest C# for this. C+++ GUI is difficult, in that QT is inaccessible and WX is hard to set up. There's C++/CLI, but that's its own brand of special, especially if you're anywhere near new to programming. C# is the most similar to both of the languages you have mentioned. You can do it in C++, but I doubt BGT has the stuff you need. C++ GUI is difficult at the best of times. Now, if we're just talking about a GUI for the blind-the normal techniques for game menus works for that, I suppose.
But a GUI a in windows with actual buttons and checkboxes is going to overturn how you've probably programmed before. It's a callback model, not a push model. That is, the entire thing is done by waiting for things to happen and letting the GUI libraries call functions you provide when they do. This is as opposed to the traditional while loop and if statements, and is foreign the first time you see it.
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