Proper place for an executable, CLI tool used by Win32 application

I have a Win32 application and I need to use a .Net command line utility that creates folders and files at the same place where it is. And I can't force it to use another place for its files.

I was naive and put it in my GUI app's AppData folder (CSIDL_APPDATA) but it works only if I'm admin. Where should I put a cli tool so my app can call it (via ShellExecute[Ex]) and where that thing can create, read and write its own files? And it should be some reliable place. And it should work from XP to Win8.

I don't know if this helps, but ShellExecute() has a parameter called lpDirectory which allows you to specify the working directory. If the utility doesn't force system to place files in its own directory, it should work.