Passing username to printer

[John Rowe]

We need to print to another print system that uses different usernames to ours.

We can do this at the command line with lpr -U username  but all attempts to use lpotions to allow people to set another username as the default for that printer fail.

Furthermore I can see no way of configuring cups to call a program as an authenticator for that printer.

Any sugestions? It seems insane to have an option that can be used from the command line but not from within an application.

Thanks

John