AppleScript to move selected Mail messages to a particular mailbox of a particular account. User is asked two times, once for mailbox, once for account to move messages to. [This script](https://gist.github.com/Zettt/6551639) displays only on dialog.

Move Mail Message Single Account.applescript

(*
Mail Filer
Files messages in Mail.app using type ahead. Display a dialog for account and one for all mailboxes of that account.

Created by Andreas Zeitler on 2013-09-13
Copyright Mac OS X Screencasts 2013. All rights reserved.
*)

tell application "Mail"
  -- choose account
	set allAccounts to (name of every account) as list
	choose from list allAccounts with title "Choose Account…" with prompt "Please select one account" without multiple selections allowed
	set chosenAccount to result as string
	
	-- choose from all mailboxes from chosen account
	if chosenAcount is not "" then
		
		set allMailboxes to (name of every mailbox of account chosenAccount) as list
		choose from list allMailboxes with title "Choose Account…" with prompt "Please select a mailbox" without multiple selections allowed
		set chosenMailbox to result as string
		
		-- move selected messages to chosen mailbox of chosen account
		set s to selection
		if s is not "" then
			repeat with currentMessage in s
				move currentMessage to (first mailbox whose name is chosenMailbox) of account chosenAccount
			end repeat
		end if
	end if
end tell