The only problem with your idea is that the eny values are changing constantly so your clipboard would have to keep pinging the server to keep it up to date. I'm sure they don't want that so, before you go into the hanger right click the map and click country status. It shows the eny in effect at that moment for each country. Then go to the hanger and select an appropriate ride. This would be the same as providing a "static" value (the value at that moment) when you went into the hanger.
