Hello,
Looking at your requirement, we would suggest you to try using our advanced automation software, Automation Anywhere that provides an 'Auto-Login' feature which allows you to unlock or login your computer when the task runs. Once the task completes successfully, it will lock or logoff the computer again.
You can download free trial version of Automation Anywhere 5.5.2 from our website:
Automation Anywhere - The Automation Software. Automate & Schedule IT & Business processes easily.
Hope that helps.