OK, I was looking for the same thing and read your post - once I figured it out, I decided to post the answer here as well.
In Task Scheduler, click Create Task. Click the Actions tab. Click the New button.
Leave Action on "Start a Program." In the "Program/script" field, type in WBADMIN. Then under "add arguments," type in:
START BACKUP -backupTarget:X: -include:c:
. . . where "X" is the drive letter of your backup drive, and "c" is your primary hard drive.
Set the triggers, settings, and conditions to whatever you like.
Image Backup does an incremental "ghost" of your HD, adding any changes since your last Image Backup, and keeping all previous backups available as well.
Thanks to the folks at microsoft and wikipedia for the info: The Storage Team at Microsoft - File Cabinet Blog : Learn more about system image backup Wbadmin - Wikipedia, the free encyclopedia