Remove exclamation mark in variable in batch script-CodePudding

I have made a batch script that tests all valid Winrar archives on a drive. It works pretty well but I have run into trouble when the file or folder name contains an exclamation mark (!).

This is where I am thus far ("ECHO !test!" is for testing purposes):

@ECHO OFF
SETLOCAL EnableDelayedExpansion
FOR /F "tokens=1,2* skip=2" %%a IN ('REG QUERY "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\WinRAR.exe" /V "Path" 2^>nul') DO SET sti=%%c
IF EXIST "%sti%\WinRAR.EXE" (
    SET PATH="!sti!";!PATH!
    SET count=0
    SET countall=0
    SET countpct=0
    IF EXIST archive_errors.log MOVE archive_errors.log archive_errors.log.bck
    FOR /R %%z IN (*.rar *.zip *.arj *.lzh *.ace *.7z *.gz *.uue *.bz2 *.jar *.xz *.z) DO SET /A countall =1 >nul 2>&1
    FOR /R %%z IN (*.rar *.zip *.arj *.lzh *.ace *.7z *.gz *.uue *.bz2 *.jar *.xz *.z) DO (
        SET /A count =1
        SET /A countpct="(!count!*100)/!countall!"
        <NUL SET /P= %%z ^(!count! / !countall! - !countpct!%%^)
        SET test=!%%z^:^!=!
        ECHO !test!
        WinRAR t !test!
        IF ERRORLEVEL 1 (
            ECHO    ERROR^!
            ECHO Errors detected in ^"%%z^" ^|