If you are selling short, what you want to use is a "buy-stop" order. This is an order that will become a market buy order if the price goes above the stop price you specify. If your software allows it, as an alternative you could use a trailing buy-stop order. This would start out with the buy point at the value you specify above the entry price and as the price moves down in the desired direction the trailing buy-stop will move down as well. If the price moves up towards the buy-stop, the trailing buy-stop price does not move up. And, of course, if you are not going to be around to close out the trade when it reaches your target price you will also need to enter a buy-limit order, as suggested above, at your target price. Usually you would have the buy-stop order and the buy-limit order linked together as OCO orders, or One Cancels the Others, so that execution of either order causes the other order to be canceled.
I am not recommending anything in particular here, but simply trying to answer your question. Look carefully at the definitions of the various kinds of orders you can use, and try using these various kinds of orders on a simulator before using them for real. Good luck.