How to recursively expand an environment variable?

rem Create the problemset "MY_ENV_VAR=%%USERPROFILE%%\some\path"echo %MY_ENV_VAR%rem One solutioncall set "MY_ENV_VAR=%MY_ENV_VAR%"echo %MY_ENV_VAR%

In the call line, the parser will replace %MY_ENV_VAR% with the content of the variable, generating

call set "MY_ENV_VAR=%USERPROFILE%\some\path"

When this command is executed, the call will force a second parse phase, generating

set "MY_ENV_VAR=C:\Users\MyUser\some\path"

Of course, if USERPROFILE contains another variable reference, the process must be repeated.

edited - Added a "solution" to the "recursive" problem and placed all the code inside a subroutine.

@echo off    setlocal enableextensions disabledelayedexpansion    rem Create the problem    set "_1first=c:\users"    set "_2second=%%_1first%%\test"    set "_3third=%%_2second%%\so & me\path"    set "_4fourth=%%_3third%%"    set "MY_ENV_VAR=%%_4fourth%%"    echo inner variables    echo -----------------------------    set _    echo -----------------------------    echo(    echo "MY_ENV_VAR = [%MY_ENV_VAR%]"    call :expandInnerVariables MY_ENV_VAR    echo "MY_ENV_VAR = [%MY_ENV_VAR%]"    goto :eof:expandInnerVariables varName    setlocal enableextensions disabledelayedexpansion    set "aux=="    for /l %%i in (0 1 100) do (        setlocal enabledelayedexpansion        if "!%~1!"=="" (            endlocal & goto :endExpand        ) else for /f "delims=" %%a in ("=!%~1!") do (            endlocal & call set "%~1%%a"            setlocal enabledelayedexpansion             for /f "delims=" %%b in ("=!%~1!") do (                endlocal & set "aux=%%b" & if %%a==%%b goto :endExpand            )        )    )    :endExpand    endlocal & set "%~1%aux%"    goto :eof