Snapshot, Virtual Copies and metadata.

[ario]

Is there any way to force Snapshots and Virtual Copies to read metadata from the original raw file after an update of the same?
I had to change the lens name on some Leica M9 files to correct an operator (me) error, and I did it by editing the exif with an exif editor and then forcing LR4 to read the metadata from the file. This worked well for everithing but the snapshots and the virtual copies on which the metadata remain as originally registered, unchanged.
Ario