Mine

@Echo Off

echo ***** Deleting obsolete log files. *****
cd logs
for %%F in ("*.*") do call :loopFiles %%~zF "%%F"
cd..
echo ***** Done deleting log files. *****
echo.
::pause
goto launch
goto end

:launch
echo ***** Launching XChat. *****
echo.
set PATH=%PATH%;lib
start xchat.exe -d "config"
goto end

:loopFiles
set A_LoopFileSize=%1%
set A_LoopFileName=%2%
::echo current file: %A_LoopFileName% (%A_LoopFileSize%)
if %A_LoopFileSize% leq 1024 goto delFile
if %A_LoopFileSize% geq 102400 goto delFile
goto end

:delFile
::echo.
echo deleting file: %A_LoopFileName%
::echo.
del %A_LoopFileName%
goto end

:end