[91892823]

Foreigner, премного благодарен! Все работает)
вдруг кому пригодится

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@echo off
setlocal enabledelayedexpansion

set "path=%path%;C:\M\"

pushd %1 || goto:eof
set "mediainfo=mediainfo --Inform=Audio;%%Duration/String3%%"

for %%i in (*.mp3) do (

for /f "tokens=1 delims=." %%j in (' !mediainfo! "%%i" ') do call:sum "%%j"

)
set "th=00%th%"
set "tm=00%tm%"
set "ts=00%ts%"

echo %th:~-2%:%tm:~-2%:%ts:~-2% | clip
popd
goto:eof

:sum

for /f "tokens=1-3 delims=:" %%i in (%1) do (

set /a h=1%%i-100
set /a m=1%%j-100
set /a s=1%%k-100

)

set /a th+=h
set /a tm+=m
set /a ts+=s

if %ts% geq 60 (

set /a tm+=1
set /a ts-=60

)

if %tm% geq 60 (

set /a th+=1
set /a tm-=60

)