Using the technique from tip 3579, Erik Remmelzwaal has scripted Whence.bat.

The syntax for using Whence.bat is:

Whence \[-p pathvar\] file1 \[file2 ... filen\]

where:

-p pathvar specifies an environment variable that contains folder paths. If omitted, the PATH environment variable is used.

Filex is one or more files that you wish to locate, specified with or without their extension.

NOTE: I have amended the script to use the executable extensions in the PATHEXT environment variable.

NOTE: If you specify a Filex without an extension, files with any executable extension, and no extension, are located.

NOTE: If you specify a Filex with an extension, only Filex is tried.

Example:

whence kernel32.dll                    returns     C:\WINDOWS\SYSTEM32\KERNEL32.DLL

whence regedit notepad explorer        returns     C:\WINDOWS\REGEDIT.EXE
                                                   C:\WINDOWS\SYSTEM32\NOTEPAD.EXE
                                                   C:\WINDOWS\explorer.exe


whence sleep filever                   returns     C:\Program Files\Windows Resource Kits\Tools\sleep.exe
                                                   C:\Program Files\Support Tools\filever.exe

Whence.bat contains:

@echo off
setlocal
if _%1 
 _ goto :error
set P=PATH
if not %1 
 -p goto :doit
shift
if _%1 
 _ goto :error
set P=%1
shift
if _%1 
 _ goto :error
:doit
set ext=%PATHEXT:;= %
:next_file
  set file=%1
  set files=%files% %file%
  call :exts %ext%  
  shift
if not _%1 
 _ goto :next_file
for %%F in (%files%) do (
 if not _%%~$%P%:F 
 _ echo %%~$%P%:F
)
goto :end
:exts
if _%1 == _ goto :EOF
set files=%files% %file%%1
shift
goto exts
:error
echo usage: %0 \[ -p pathvar \] file ...
:end
endlocal