https://blogs.technet.microsoft.com/filecab/2013/08/20/dfs-replication-in-windows-server-2012-r2-if-you-only-knew-the-power-of-the-dark-shell/

(Get-DfsrBacklog -GroupName "RG01" -FolderName "RF01" -SourceComputerName SRV02 -DestinationComputerName SRV01 -Verbose 4>&1).Message.Split(':')[2]