Use the permissions system per forum. You should create a new forum for this specific use.
Permissions are per User Group, Forum, and Site. Between these, you will need to research what is best for you needs.
These settings would be something you need to research as related to your forum.
HINT: Create a new user group that has access to move/merge and approve/unapprove posts for that forum. As an example, a forum moderator will be able to perform these tasks.
The moderator key items being used are:
1/ Able to approve/unapprove posts, which are specifically for the purpose you're asking for. Unapproving posts are new for UBB.threads 7.7.4.
2/ Move/merge posts.
As always, be mindful of who you give moderator permissions to