Originally Posted by mjamm

Another option is to use a script if you have Procomm.

Another option if your PBX is connected to the LAN, is to use a program called ZOC from EmTec - Terminal Emulator, Telnet and Secure Shell (SSH/SSH2) Client and Comm. Software for Windows

ZOC will allow you to connect to the PBX using the Rlogin protocol and run a script. They are very fast and you can touch all 400 phones in about 20-30 minutes (If not faster).