Actually, you have good english
To launch with proxy run a command line command:
powder-sse(2/3) proxy:{address}:{port}' where {address} is the address of the proxy and {port} is the port.
this is my code of the batch
@echo off
title Tpt launcher
rename "%UserProfile%\Downloads\Tpt launcher\versions\versions\powder-win32" "powder-90.2-win32"
rename "%UserProfile%\Downloads\Tpt launcher\versions\versions\powder-win32 (1)" "powder-91.1-win32"
:menu
cls
echo Your last type in normal menu is:%releasever%
echo If your version is beta, please, type "beta"
echo To cancel this press any key
set /p releasecode=What folder contains your version? (In N° of version)(In Downloads)
setx releasever %releasecode%
if %releasecode%==beta goto betaver else goto releasever
:releasever
cd "%UserProfile%\Downloads\Tpt launcher\versions\versions\powder-%releasecode%-win32"
start Powder.exe
goto menu
:betaver
cls
echo Your last type in beta menu is:%betaver%
echo Type "menu" to return
set /p betacode=What folder is your beta version? (In N° of version)(In Downloads)
setx betaver %betacode%
if %betacode%==menu goto menu
cd "%UserProfile%\Downloads\Tpt launcher\versions\versions\powderbeta-%betacode%-win32"
if %betacode%==43.0 start powder-sse.exe
if %betacode%==42.0 start Powder.exe
goto betaver