First post of a user in a thread

[Fresky]

Hi friends.

I need to identify the first post of a user in a thread, using a "if condition" sentence.

I know that "<if condition="$post[postcount]==1">" identifies the first post in a thread, but what I need is to identify the first post for every user in a thread.

Maybe there is a variable that I can use in the "if condition" sentence, but I have been looking for a list of variables with no success.

Could anyone help me?

Thank you.