Oh my gosh, I hadn't even thought to look there. It seemed like so much of the avast! configuration was unavailable through the ADNM console, but I was completely missing these options.
In case anyone doesn't understand exactly what we are getting at here, the "Default Resident Task" is listed under "On-Access Scanning Tasks." It took me a while to find it, even after edj pointed me in the right direction. If you view the properties of this task, you will find all the options you would find in the on-access scanner settings on each of the clients.
Thank you again for your help. I am very excited about using avast! on our network as it is a far superior solution to anything we have had in the past!