Alternative email adresses / add alias adresses via variables

Hi there,

we would like to add additional mail domain alias accounts to all our existent users via bulk editing.
So basically i thought that adding


to the alternative mail address fields would do the trick.

However it seems, that


will not be replaced with the username, instead, the values are entered exactly as entered for the users.
Any idea, how to approach instead?

For new users, we edited the corresponding sections in our user creation template, and it works exactly like expected.