WOLVENHEART13'S PROFILE

author=ldida1
In the troop editor, right click on an added enemy and press "Appear Halfway"

Then you use event commands to make it appear. (You would have to make an attack that turns a switch on, then in the troop event make the foe appear if that switch is on)

author=Trihan
Not entirely related to the method Marrend told you, but you can actually create a treasure chest automatically by right clicking on the map tile where you want it, selecting the Quick Event Creation submenu, and choosing "Treasure Chest..." You'll be prompted to select the chest's graphic, and whether it contains gold or an item. This will automatically fill in the event code, but you can edit it afterwards if you want to have more than one item.

The automatic creation will also make the chest turn its own A switch on so that it only gives out its loot once, and automates the opening animation and item gain message.