Hmmm... I've never actually tried that. As far as I see, there is no real way to get rid of item which is on the board already when you enter it, especially moving one... Even if there is, item will reappear as you enter board again... Propably Xorlak knows the way.
You can make 2 versions of that board, with item and without, then send player to the second board by using #send("board-name-here",playerx[0]!,playery[0]!,playerz[0]!) - it will send player to another board, using variables indicating where he already is, so he will appear at the same place but on another board.