Pluszeichen in Dateinamen finden und ersetzen

(=20:16:40  D:\temp=)
>echo x>"e:\schnipsel\Fritz + Willi.jpg"  

(=20:16:51  D:\temp=)
>for %i in ("e:\schnipsel\*+*.*") do @set "x=%~nxi" & @echo ren "%i" "!x: + =_!"  
ren "e:\schnipsel\Fritz + Willi.jpg" "Fritz_Willi.jpg"  

@echo off & Setlocal EnableDelayedExpansion
for %%i in ("e:\schnipsel\*+*.*") do (  
   set "x=%%~nxi"   
   echo ren "%%i" "!x: + =_!"  
)

@echo off & Setlocal
for %%i in ("e:\schnipsel\*+*.*") do  set "x=%%~nxi" & call :RenameOneFile "%%i"  
goto :eof
~~~ Raum für Notizen

:RenameOneFile
   echo ren %1  "%x: + =_%"  
goto :eof