> I am not sure about the difference in semantics between powershell and 
> command prompt with respect to quoting since

CMD only uses single quotes in `for /f` loops, in which it's either a command or a literal string (w/ the "usebackq" option). This is not a problem in activate.bat. 

Double quotes in file names generally shouldn't be a problem in Windows. As far as I know, only the named-pipe file system allows them in pipe-file names (e.g. r'\\?\pipe\"pipename"'), and for regular files they're allowed in stream names (e.g. 'filename:"streamname"'). Otherwise, double quote should be reserved in file names as the DOS_DOT wildcard character.