How to close executable called with dos()

I am using

 dos('thermo.exe')

to run the executable. This exe does something and then spits out a text file of results. However, the exe never closes and so MATLAB continues to be busy. How can I have matlab automatically close the executable when it is finished? When the exe is done, it prints "I am done!!!!", maybe I can use that?

Edit: alternatively, I can have matlab realize that it is done and move on without closing the exe.

Thanks.

[Geoff Hayes]

Christopher - what happens when you run the thermo.exe from the command line? Does the exe terminate successfully, or does it not "close" either?