Make sure data network cables are plugged securely into the wall and your computer. Sometimes they appear to be in but are actually loose. Close all programs and save all documents. Look at any files that match size, date or name. If still no luck you most likely lost the most recent changes.
Decision needs to be made about re-typing recent changes from printouts or restoring from backups.
Ask Iain or John when last backup of your machine was. Could be up to 6 months old. Check other places, names, dates and similar sizes for the file. Call Iain for tape-restore, give date range of versions, filename, directory, etc. Restore file from the NetWare server's nightly backup.