Pobega

I am writing a script for a private game server, where the php has to fetch the output of a .exe file (The .exe file can be accessed through IE). The idea is to automate the registration, so people can enter an E-Mail and a password and get a new serial or fetch an already made one. The question is, how do I fetch the output from the .exe using php? Will the .exe run (As in, when you access it it uses an algorythm to make you a Serial/Access Key), or will it just mess up? Thanks for your time. I know how to do the php if this were a normal file, but I'm not sure if the include(); function actually executes the targetted page/file.