Exclude locked files

Is it possible to configure a file exclusion for B&R 10 Advanced Server that will keep locked files within a specified directory from getting backed up?

Here is the situation... We use Perforce in our work environment. The workers sync to a file depot (files are copied from the server down to their local storage), check out the files they need, make changes and then check them back in. The files that are synced are locked until the user checks out a file. Checking out a file only unlocks that file making it writable. Our depot (file store) is about 130GB but the typical user only has a fraction of those files checked out for modification. Since we do not want to backup the whole depot for 50 PCs, we've excluded the path to where the files are stored. The down side is that changes that people have saved but not yet checked in do not get backed up.

In this case if there were a way to exclude the backup of locked files from c:\Depot and allow the backup of unlocked files for the same path, that would allow us to target the files we need.

So, does anyone have any ideas or suggestions? Surely there are other Perforce users out there.