Replace asterisks in BAT variables

set-ast.bat

:: Replace all asterisk characters in a variable

:: Usage:
:: set-ast <variable-name> <replacement-value>

@echo off
@setlocal enabledelayedexpansion

set variable=%~1
set value=!%~1!
set replacement=%~2

:loopback
  set righthand=!value:**=!

  if ["%value%"]==["%righthand%"] (goto quit)

  if ["%righthand%"]==[""] (
    set lefthand=%value:~,-1%
  ) else (
    set lefthand=!value:%righthand%=!
    set lefthand=!lefthand:~0,-1!
  )

  set value=%lefthand%%replacement%%righthand%
  goto loopback

:quit
for /f "delims=" %%v in ("!value!") do (
  endlocal
  set "%variable%=%%v"
)