Hidden the Author in specific broad

[salad]

I was building a photo forum, and designed a broad to let every forum's member can post their photo to everyone criticize.
But this specific broad has something special, for all of the forum's member, Author/poster name will be automatic hidden or changed the display to a specific username when the topic/post display on the screen, to prevent another member know who was created the topic or replied the post.
But i don't want to change the Author/poster during the data insert or update directly, because i want to give the way for the admin to monitor the broad, i just want to hidden the poster when the topic/post displayed.

Anyone has idea for this? Any people do the same before? Anyone need this function? please let me know.
I was studying the forum structure right now , but i just a beginner in SMF, so we need you help.
Temporary, if no similar MOD handled it before, i will try to do it and give it for everyone need.