Mass Downloader Antivirus Scan

I use Mass Downloader 3.3.698 SR2 for most of my downloading. I have managed to set Avast AshQuick.exe to scan downloaded files but Mass Downloader ask me to: “Please type necessary antiviral program command-line parameters” in order to complete the setup. I have searched far and wide in Avast Help and on the web for the correct parameters, all to no avail. Can you advise me as to the proper command-line parameters I should enter?

avast does not require any parameter, I mean, ashquick.exe is enough.
Does Mass Downloader require any parameter?