C++ Start Process / Apllication : I have a dll source file, I want to create a function in it, which call an exe.

The exe is in the Data/Common/PPI.exe How can I start this from the c++ code?
I tryed with CreateProcess and ShellExec, can anybody create an example for me to know how to make it, with this path and with this exe name.

I dont want to add the full directory path because if its changed or something I need to rebuild the exe... so the dll is in the root folder the dll call this function and the function start the Data/common/PPI.exe, thats it all.

Thanks!