How to Export a specific Public folder from a Public folder archive using 'Export-EVArchive' PowerShell Command

Problem

How to do an export of a specific Public Folder from a Public Folder archive in Enterprise Vault (EV) using the 'Export-EVArchive' PowerShell Command.

Cause

Because the Export Archive Wizard is restricted to show only mailbox and journal archives, the Public Folder archives don't show in the list of archives to export. 

Solution

1. Run the following query against the Directory database and mention the Archive ID of the public folder archive. This query will list all PF and sub folders:
   Select * from ArchiveFolderView where ArchiveVEID = '<Archive ID>'
2. Copy VaultEntryID of desired public folder or subfolder.
3. Use the following PowerShell command to perform the export while mentioning the Archive ID as well as the VaultEntryID:
   Export-EVArchive -ArchiveId "Archive ID" -OutputDirectory "d:\pst" -SearchString "pvid:<Vault Entry ID of public folder>" -Format PST -MaxThreads 25 -MaxPSTSizeMB 51200