I think he wants an addon which when people use it and paste in a block of code it saves it with an id..
I save one or paste one in now...the whole block is stored with an id of 0, next person to save a block would get an id of 1 and so on in a serial fashion. I assume this is also so people can refer to the code block id to search, embed or connect code to a person or something along those lines.
I've done something like this but it is completely independent of xenforo so there would be no way for a block of code to be tied to a user id in the script's current state.