http://bugs.winehq.org/show_bug.cgi?id=19784
--- Comment #2 from Dan Kegel dank@kegel.com 2010-01-01 15:41:39 --- There is partial support for ( and ) in cmd; see WCMD_ReadAndParseLine in wcmdmain.c
http://source.winehq.org/git/wine.git/?a=blob;f=programs/cmd/wcmdmain.c;hb=H...
and in fact if you type just ( by itself on the commandline, wine's cmd prompts you properly for more lines. It just doesn't seem to handle ('s inside if statements properly.