How to Locking phone keypad With password?
I think nothing is available public for this, please try contacting technical support.
lock screen how to make cell-like product 'Advanced Device Locks Pro'?
Posting the same information again here for you -
This can not be done with regular/PUBLIC API's
You would need to partner the API from here: http://www.developer.nokia.com/Resources/Support/ (Create a ticket).
This request is not free and might not be granted if your use-case and company details do not check out to be valid.