To add these people to your userlist manually:
or in a popup:
menu nicklist {
add greet:.guser GREETEM $$1 3
}
Or if you meant "if {]TDN[} is part of their nick" then use
/auser GREETEM *{]TDN[}*!*@*
Then in your remotes:
on @*:JOIN:[color:blue]#channelname[/color]: {
.msg $nick [color:blue]your greeting goes here[/color]
}