Using an external IDE

I’ve read from time to time about people testing their solutions with Visual Studio.
I’d like to set this up. I often use CodinGame Sync on Chrome to code my solutions in emacs, and I’ve also synced emacs to Visual Studio at times, and I think if I could integrate this more, I’d be able to get better at using VS+emacs while playing.

As far as putting my code into the Cg IDE, it’s fine, the Sync plugin does that just fine, but I’d like to try doing the test runs locally.
I see that, for some bizarre reason, VS doesn’t allow redirecting stdin, stdout and stderr directly. It always pulls up an external window - annoying as *****.
I can create a text file in the project folder and setup VS to read it for stdin by setting Project->Properties->Debugging->Command Arguments to:
< “$(ProjectDir)\input.txt”

OK, but stdout… Has anyone found a way to do this? I mean, I could just use a “res” variable, and then look at the value of the res variable in VS, right? But sometimes, to be fast, I print an expression instead of a variable.

Also - has anyone worked out a way to do this with all tests at once? To have them all written in the input file, but solve one after another? Doesn’t quite seem possible. I mean, to have the same code then work directly on submission…