This article may have already been seen in your quest for a solution. Although the article is for the VL B405 the EWS (embedded web services) will look the same.
I hope this helps.
I suggest calling into the support center at 1-800-821-2797 or 1-800-835-6100 they can guide you step by step in setting this up.
Just setting up a C7020 to work with my Mac. Printing fine but trying to set the scanner up to operate to a 'Destination' is somewhat bewildering (admitted, I'm a designer, not a tech) and I know the basics but what is the best route to scan to the desktop? Checked out videos and posts and none the wiser.