[Mailman-Users] Setting language on e-mail subscribes?

[Steven Bonisteel]

Is there a command available via the e-mail interface to have a subscription request set the preferred language at the same time?

We would like the language of the confirmation process and the eventual welcome message to be set to a preference selected by the user (in a front-end form) *before* they are actually members.

So, basically, we want to do via e-mail what you can do in Mailman's own Web interface for subscriptions.

(In this case, the Mailman server is not accessible to the sign-up site.)