[Iska]

Не проверялось:

Код:

@echo off
setlocal enableextensions enabledelayedexpansion

set /a iSumL = 0

for /f "usebackq delims=" %%i in (`dir /b /s /a:-d /a:-h "c:\*.log" "c:\*.temp" "c:\*.tmp" 2^>nul`) do (
	2>nul del /f /q "%%i" && set /a iSumL += %%~zi
)

echo %iSumL%

endlocal
exit /b 0