double quote in Windows batch script not working

I have following code in my batch command file.

set EXEC_DevEnv="C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE\devenv.com"

    if not exist %EXEC_DenEnv% (
        ECHO.
        ECHO ERROR: Unable to locate DevEnv.exe. Make sure that Visual Studio 2005 is installed.
        goto endIncomplete
    )

The file devenv.com is there in the path in the c:\ drive. Yet when I run the file, it complains that devenv.com file not found.

How can I set the EXEC_DenEnv such that when batch file runs it does FIND the file because it does actually exists