I think I got probably the dumbest question here.. but, here goes.
I want my labview program to open an exe file, so i stick the "open file" sub-vi right outside my program loop, wire a data path, Then I connect the error out to the loop.
Using "highlight", I see that it finds the file and says "ok: but the file won't open...
You have to input the exe file's name as a string into the command line input, just as if you were calling it from a command prompt. You can also wire the entire path with file name as a string into the command line input and then you don't have to wire anything into the working directory input. If you have other files in your working directory that your exe needs to access, you could put the path into the working directory input and the exe filename only into the command line input.