How can you change ident, which shows up as ident@hostname.com on ircll?

I know the nickname and the real name field can be changed with environment variables such as IRCNICK and IRCNAME. However, the documentation does not tell you how the ident is changed. (The ident is the name that's used when you /whois nickname, and it shows up as part of **ident**@username.com in the host field, and the bolded part is what I'm trying to figure out how to change) I'm wondering if this is possible on the ircll client.