Changing background image of logon screen programmatically?

Question

I'd like to replace the bitmap on the logon screen of Windows 7 64-bit with one that is on disk. I have a program that periodically switches the background image of my desktop, and it has a configuration to run a program after it has changed it, which I thought I could use to also copy the same bitmap to the logon screen.

Does anyone know how to do that, or even if it is possible? If someone knows a handy command line utility to do it, that would of course be nice (but then I suspect this question should be migrated to superuser.com first), but if someone has some API commands that would help, that would be more than enough.

I found an article which detailed a dll and some resources I would have to replace. That sounds a bit too hackish for this.

Answer 1

I typed "change background image logon screen windows 7" into a search engine and the first link was: this which seems to show how to do it. Now you just need to figure out how to write a program to automate the steps.