Changing user?

I want to apologise if this is in the wrong spot first of all. Okay so here's my problem:

I created a forum previously using a different hosting site, so there were already a bunch of posts made! I have copied and pasted them using quotes so people know who posted what. I know on the previous forum I was able to change the poster for example:

Posted by Registered User 1
(Fiddle around with some mod/admin stuff and then it becomes)
Posted by Registered User 2

And I was wondering if I could do that here too? Cause I really want the posts to go to who they belong instead of having my name there and theirs in quotes.

Thank you!

Hello,

I'm sorry but this is not possible here on forumotion at the present moment

Thank you very much for letting me know!

Your welcome, glad to have assisted,