I've created a batch file to run a bulk export on appengine to a dated file

@echo off

FOR /F "TOKENS=1* DELIMS= " %%A IN ('DATE/T') DO SET CDATE=%%B
FOR /F "TOKENS=1,2 eol=/ DELIMS=/ " %%A IN ('DATE/T') DO SET mm=%%B
FOR /F "TOKENS=1,2 DELIMS=/ eol=/" %%A IN ('echo %CDATE%') DO SET dd=%%B
FOR /F "TOKENS=2,3 DELIMS=/ " %%A IN ('echo %CDATE%') DO SET yyyy=%%B
SET date=%yyyy%%mm%%dd%

FOR /f "tokens=1" %%u IN ('TIME /t') DO SET t=%%u
IF "%t:~1,1%"==":" SET t=0%t%
@REM set timestr=%d:~6,4%%d:~3,2%%d:~0,2%%t:~0,2%%t:~3,2%
set time=%t:~0,2%%t:~3,2%

@echo on

"c:\Program Files\Google\google_appengine\appcfg.py" download_data --config_file=E:\FEEDSYSTEMS\TRACKER\TRACKER\tracker-export.py --filename=%date%data_archive.csv --batch_size=100 --kind="SearchRec" ./TRACKER

I cant work out how to get it to authenticate with google automatically; at the moment I get asked the user/pass everytime which means I have to run it manually.

Any Ideas?