Variables in language strings.

[eluser]Young Caveman[/eluser]
Hi to you all.

There's no problem when i have to display a message like:

"User added Successfully."

What if I have to display ALSO the username of the user just created? I can't specify the username in the language files cause obviously the username is changing everytime a user is created.

"User [USERNAME] added successfully". <-- It is possible to do this? And if yes , how i can do that?

Thanks in advance.

Don ~ Alberto (Italy, so please try to undestand my english ;P)