There's no direct support for this in the application, but you can use one of the xterm emulation features to do just this.
Try the following script:
http://www.celestialsoftware.net/telnet/nameit.gz
You'll have to dowload it to your *server*, uncompress it, and make sure it has execute permission. Once there, you can do this from the UNIX command line:
nameit 'name of the window'
to change the title bar of the window. It's not necessary to be using xterm emulation for this to work, as the script will work no matter which emulation is being used. However, your OS (RedHat for example) may try to use this same feature to name the title bar with the current username and/or path and override your selected title. There are ways to turn off this default behavior, if necessary.
Let me know if this helps...