Well, I´ve explained in the wrong way.

I need the path to the project, even if it´s published and located in a different folder.
Then I need the path to this folder, where the exe is located.

In develoment it´s my project folder d:\bla\bla
Published and installed it´s c:\programm_files\bla

Simply the folder where the project / the executable lies, published or not.

The predefined "work_dir" contains indeed this specific string.
I´m aware (and it´s logical) that it has to be different on other machines.

Edit: Here´s what I do:

I load a bitmap through a file open dialog. This bitmap is in a different folder than my app (published or not).
The file open dialog sets the current directory to this folder, thus allowing the engine to load the bitmap.

After that instruction I need to set the current directory back to my application directory, because I want to load
content from it.