Replacing [blabla-userid] with user-account-name

[Twisted-R]

Is it possible to have a certain code that can be posted in posts that does the following:
It gets replaced the name of a useraccount (user name).
I don't mean the name of the person looking at the thread (I already know such a code exist but I'm not looking for that.)

The code would for example use the user-id-nr to be replaced by the account's username. (and thus can be used for any accountname.)
The purpose of this being to avoid having to change posts with lists of names...whenever someone gets their username changed.

Does anyone know if this is possible? and does anyone have a hack/mod/code for this? (And if not..could anyone make one?).

Thanks in advance for any help anyone can provide.