I've used this feature a few times to do exactly what you're hoping for.
As an Admin or Mod with "Edit any post" permissions (bottom-right at Control Panel > Forum Permissions);
1. Click "Edit" on the individual post you want to move. Not the OP, but the one which is OT. 2. Click "Move/Merge this post and any replies." 3. Select the top option, "Move post & replies to:" and from the drop-down list, choose the forum you want the post and its replies to be moved to. 4. Click submit.
SEE ATTACHED IMAGE
[EDIT] Giz, are you asking for an option to "Move Single Post" WITHOUT its replies?
ALTERNATIVELY: Edit the user's post to replace its text with something such as:
--- ADMIN EDIT: Off-Topic Post Removed. To increase the discussion quality, it is imperative that we eliminate "off topic" posts, and those which derail the current discussion topic.. --- OR --- ADMIN EDIT: Trolling / "Off Topic" Post Removed. To cut down on the abuse and to increase the discussion quality, it is imperative that we begin to eliminate "off topic" posts, and those which are obviously posted for the intent to troll. ---
Threaded mode never really worked with v7, and as such the replies aren't always nested with the post they belong to; so yeah: [EDIT] Giz, are you asking for an option to "Move Single Post" WITHOUT its replies?
I can see how this would be a simple hack to implement.
In the templates/default/editpost.tpl, you would add code to display a button only admins and authorized moderators would see that says something such as, "Convert Post To New Topic." This would allow whoever is moderating the posts, to rename the post's title before he separates it from the discussion (IMPORTAINT!)
In the following step, scripts/doedittopics.inc.php would check if the "Convert Post To New Topic" button was pressed. If YES, it modifies the ubbt_POSTS table with the new information (such as this new topic's title and removing the "Re: " from the beginning of this /new topic title/), along with updating the following fields: POST_PARENT_ID gets changed to 0. POST_IS_TOPIC gets changed to 1. TOPIC_ID gets the next available TOPIC_ID index number.