>REM Here is my bat file called test.bat
>@echo off
>
>RetTest

In addition to the other message, this is not the correct mechanism to check the errorlevel return value. Instead, you should use an IF branch based on the errorlevel code - it is a number, not a string.

IF ERRORLEVEL 2 GOTO TWORHIGHER
IF ERRORLEVEL 1 GOTO EXACTLYONE
REM if it falls through to here, a zero was returned
echo The big zip
goto end
:TWOORHIGHER
echo something bigger than 1
goto end
:EXACTLY1
echo It came back 1
:END

This is documented in the Windows Help file, and the behavior is consistent since DOS 2.0 for examinign an error level.

>goto answer%ERRORLEVEL%
>
>:answer0
>echo Zero was returned
>goto end
>
>:answer1
>echo Negative one was returned
>goto end
>
>:answer
>echo Nothing was returned
>goto end
>
>:end