2which

@echo off
set way=%cd%
set var1=%1
set var2=%var1:~-4%
set var3=%1.exe
set answer=1
if /I ".exe" EQU "%var2%" (set var3=%1)
if EXIST %var3% (
    set answer=%cd%\%var3%
    ) else (FOR /F %%i IN ("%var3%") DO set answer=%%~$Path:i)

cd %answer% 2>null
if ERRORLEVEL  1 ( echo %answer% )
cd %way%
exit /b