@ECHO OFF
IF NOT "%OS%"=="Windows_NT" GOTO Syntax
IF      "%~1"==""           GOTO Syntax
IF NOT  "%~2"==""           GOTO Syntax
DIR /A-D "%~1" >NUL 2>&1 || GOTO Syntax

SETLOCAL
FOR /F "tokens=1* delims==" %%A IN ('ASSOC %~x1') DO @FOR /F "tokens=1* delims==" %%C in ('FTYPE %%B') DO CALL ECHO.%%D
ENDLOCAL
GOTO:EOF


:Syntax
ECHO.
ECHO StartHow.bat,  Version 1.00 for Windows NT 4 and later
ECHO Display the command actually issued with the START command
ECHO.
ECHO Usage:    STARTHOW  filename
ECHO.
ECHO Where:    "filename"  is the file that you want to find the START command for
ECHO.
ECHO Example:  STARTHOW  C:\boot.ini
ECHO Returns:  %windir%\system32\NOTEPAD.EXE C:\boot.ini
ECHO Meaning:  START C:\boot.ini will open C:\boot.ini in Notepad
ECHO.
ECHO Note:     Programs like UltraEdit have been known to break the association.
ECHO.
ECHO Written by Rob van der Woude
ECHO http://www.robvanderwoude.com