\Program Files\Trend Micro\OfficeScan\PCCSRV\Private
Add the server name anywhere after the "=" sign.
LicenceExpire_Subject=Attainity [Trend Micro Security Server]License expiration
LicenceExpire_Message=Your license will expire within %CT days or may already be expired. Contact your Trend Micro reseller to purchase a new Activation Code and reactivate your license. Refer to the Live Status screen on your Security Server for further instructions.
If you wish, you can customize these messages to whatever you choose. Just do your editing after the "=" sign.