AbleCommerce Shopping Cart Software

I'm not seeing any place in the admin screens to apply a coupon to an existing order. I can add an order item for a discount, and make it look like the coupon. But that doesn't include this order under the coupon reporting.

Is there something I'm missing somewhere?

Read following thread which is about Gift Wrap, try same thing but instead of Gift Wrap remove statement saying Coupon instead and see if it works or not.
viewtopic.php?f=42&t=12615