I don't think the functionality for choosing random names from a list is built into Kareha, and I can't really see Squeeks adding to it for something like this.
And tripcodes don't work in default names. Note /code/'s "#!/usr/bin/anonymous", for example. And I tried using "MODD#withtripcode" on a elitistsuperstructure.net board, it showed as "MODD#withtripcode" and not "MODD!5JrU4QOlH6".