http://bugs.winehq.org/show_bug.cgi?id=16246
--- Comment #5 from Aziz Köksal aziz.koeksal@gmail.com 2008-11-28 18:25:47 --- (In reply to comment #4)
If you don't want to set it globally then instead of launching whatever program you are running under Wine directly, modify the PATH environment variable as part of a batch file which then runs your program.
That would be a workaround, but still not something that just feels right. It has to be the most optimal solution, documented and easy to understand for users and programmers. I can only see WINEPATH being that. Keep in mind that on a Windows command line you can just do "set PATH="%PATH%;C:\new_path" and then launch your program. Also, if you have a Python script on Windows, you can just modify os.environ['PATH'] before calling an external program to achieve the same effect. I want to be able to do the same thing on Linux, by modifying os.environ['WINEPATH'].
In the meantime, I will have to use the batch file workaround.