Changing upn userPrincipalName

is there a way to add an alternative UPN suffix and change the userPrincipalName of users inside the Univention Management Console?

Not every one of our users gets their own email address, so every user gets the username “first letter of name + surename”.
Because Outlook uses the UPN, it doesn’t connect automatically, so I want to rename every UPN with an email-address if there is one.

I can change it, if I use the Microsoft AD Tools. And although I didn’t test it, it shouldn’t be to difficult to change userPrincipalName directly in LDAP.

But I would prefer to not have to change it, when creating a new account. The easiest way to set the UPN when creating new users would be, if the UPN could be set inside the univention templates. Is this possible?

Does nobody have an answer to this?