http://bugs.winehq.org/show_bug.cgi?id=28645
--- Comment #2 from Louis Lenders xerox_xerox2000@yahoo.co.uk 2011-10-11 13:51:22 CDT --- Created attachment 36826 --> http://bugs.winehq.org/attachment.cgi?id=36826 patch
it appears that DoEnvironmentSubstA is already more or less implemented, so a simple copy and paste patch is enough to fix this bug (try the attached patch)
i'll see if i can add some tests as well