Update (lag time again...):
I have a program installed called "MinGW." With it I can compile C++ files into EXE files, and they do run.
Another installed program, "TurboC++," works nicely but only within itself. If one can use those files for anything else, including DOSBox 0.74, I haven't figured it out yet; if those dates mean anything that's a bit unlikely.
Eclipse now runs, and after reinstalling MinGW- the default installation was not in the "C:" folder which is where it should have been installed- I managed to clear up some troubles. I'm not 100% sure how I did the other part.
Now when you try that sample "Hello World" program it runs: the ".CPP" file appears in a sort of Notepad program; the EXE program produced will not work unless two DLL files- "libgcc_s_dw2-1.dll" and "libstdc++-6.dll"- are added to its folder, but once they are when you run it through Eclipse you get that "Hello World" in the little command window at the bottom of the screen.
Running the EXE program directly with the MinGW command window works nicely, and those two .DLL files need not be in the same place.
I've modified that program to do some basic math and to put a rectangle made of "*" on the screen, but the RAND() does not work, and trying to include "stdlib" does nothing. Either a needed file is missing or Eclipse handles it differently than in the O'Reilly manual.
All right, then- I'm this far. Apparently Eclipse is going to be the app I use here. It's "Version: Helios Service Release 2 Build id: 20110218-0911;" an older version but hopefully it's good enough. I don't want to jinx anything now that I actually managed to get this far; at least looking back over the replies I have some idea what the technical terms mean. C++ has things in common with Ruby and Javascript.
Note that Visual Studio fails to do anything with anything. The "<iostream>" error is still there. Maybe I should just uninstall it, I sure don't want to deal with Microsoft customer service if I can avoid it.
Again, thanks to you all here.
Hopefully Eclipse can be used to work on SCUMMVM. This is the code used for my initial program:
//============================================================================
// Name : helloworld.cpp
// Author : GusCE6
// Version :
// Copyright : Your copyright notice
// Description : Hello World in C++, Ansi-style
//============================================================================
#include <iostream>
using namespace std;
int a = 5;
int b = 2;
int c = 10;
int g;
int main() {
cout << "!!!Hello World! At last this works, yae!" << endl; // prints !!!Hello World!!!
cout << " This is an actual C++ program- really!

" << endl; //More stuff...
cout << " " << c << "-" << "(" << a << "+" << b << ") does equal:" << endl;
cout << " " << c-(a + b) << endl;
cout << " ***************************" << endl;
cout << " * *" << endl;
cout << " * *" << endl;
cout << " ***************************" << endl;
return 0;
}
Curiously enough trying the RAND() command does not work, because that INCLUDE-STDLIB part from the O'Reilly manual is not recognized.
Update: I just found out how to get random numbers generated. But it's like a scavenger hunt!