It might be a worthwhile venture to investigate starting the spreadsheet as a scheduled task (ensuring you've logged in at least once with the account to be used to create a profile), but failing the ability to do that, here's the general guideline.
- We need to create some entries in HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon that will set the machine to autologin. You can either script these, or manually regedit them to set them to what you want, then export the key.
I haven't tested this with Vista/7, the last time I used it was NT and I haven't time to test this for you right now, but here's the general guideline:
Run this CMD as a scheduled task every so often:
quser|find /i "console"|find /i "myuser"
if not "%ERRORLEVEL%"=="0" goto :INITIALIZE
: set logon credentials
reg add "HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon" /v "DefaultUserName" /t REG_SZ /d "myuser" /f
reg add "HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon" /v "DefaultPassword" /t REG_SZ /d "S3cretstuff" /f
reg add "HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon" /v "AutoAdminLogon" /t REG_DWORD /d 0x1 /f
shutdown /r /f /c "auto processes not found running"
You might also look into something called "registered applications" - it's mentioned in the shutdown help, I've never heard of it.
This should get you started.