How can I get my current folder path (how can i run a "setup.exe" file from an unknown path)

Hi everyone,

Short story:
I want to run an exe file ("setup.exe") but I don't know its path and in different computers the path will be different so I can’t use a specific path. How can I do it?

Long story:
I’m trying to run an exe file that is place in a zip file.
The zip file has a unique name so I shellexecute it but the exe file name is setup.exe (which is not so unique ) , how can I get the current folder path so I could run the exe file. or any other suggestions on how to run it without the path? it is the current folder I'm at.

thanks !