C++ Networking Help

I'm making a database program, so I thought it would be fun to store proxies in it. But I want to be able to test the status of the proxies, i.e. see if they are in working order. However, my Comp Sci teacher doesn't work with networking via C++, so he can't answer my questions.

I thought that pinging would have to be a step in determining if the proxy works, but I'm not really sure. I did some research on the "system" function to run dos commands but I couldn't get it to print anything viable.

Is there anyway to test if a proxy is working?

I use the crappy Turbo C++ compiler if that is any help. (I use it for it's sweet graphics library)