This is not a setting that can be changed in the config file.
A host comes in the form of nick!
user@host.name
Where,
nick = the irc nickname
user = the username on your shell account
host.name = the hostname the bot is running on
This is a feature of the indentd program, that allows a server, to see exactly which user, is trying to contact it via a certain port.
Unless you admin is willing to disable the identd program, then you can't change it.
If he where to disable it, the name would be prefixed with a ~
EG
nick!~
user@host.name
Which can't be removed.