Delete old backups when disk is no longer available

Hello all,

Regarding Windows Server Backup on Server 2008 Standard:

I understand that I can delete non-system state bakcups by deleting the shadow copies on the disks that store the backups. This is necessary for the "Total backups" counter and "Oldest copy" date to truly reflect the backups that are actually available.

My question is, is there a way to do this for disks that have been formatted and no longer have the original shadow copies to delete?

Any assistance would be much appreciated. Thanks