thanks for the replies so far guys much appreciated.
What i am trying to do is have it so that the av will automatically update and then scan the drive, without any user interaction if at all possible.
If I can get it to work, then I will be able to pass it onto my bosses, who are potentially looking to sell something like this to a customer. And they would require a proper licenced product.
other av's i have been looking at appear to have an option like /remdrives so that i can force scan the removable drives.
thanks once again!