I remember that DOS (command.com, not CMD.EXE!) needed help with that even back when we booted to DOS with the config.sys file. Let's google it?
http://social.answers.microsoft.com/Forums/en-US/w7programs/thread/4ef98b5f-c613-4d90-8133-d10399383f61 makes me recall how we had to fix this in NT and beyond. Do you remember that?
When testing a DOS app on a new WINDOWS 7 PRO system with a French kboard I have discovered that Windows toggles to the ENGLISH kboard when the .exe file is run. The app has been compiled on a XP PRO system and has been running on all versions of Windows so far.
More amazing is that the DOS screen on the W.7 system does manage the french keys.I compile multiuser business apps. with QUICKSILVER 1.3 1989 from WORDTECH SYSTEM which are often running in background while the users run MS OFFICE programs in foreground.Is changing the cmd.exe in the W.7 system32 a solution ?