LCSCmd installs with Office Communications Server 2007 R2 Core Components (osccore.msi) and the Administration Tools (admintools.msi), but it can also be run from the CD or a share. By default you'll find LCSCmd.exe in the Program Files\Common Files\Microsoft Office Communications Server 2007 R2 folder. LCSCmd isn't added to your path, so you'll need to either add it to your system path or navigate to this folder to run it.