I have Dawnguard installed and I have an enhanced crossbow and a bunch of steel bolts. I also have the exploding bolts of fire, frost and shock. If I load up with, say, bolts of fire and I run out. I automatically switch to the standard steel bolts. I would like to have my archer choose one of the the other exploding bolts. Is there any way to control what order she chooses them in?
Thanks.

Yep, don't carry the bolts you don't want to use. The game will default to the lowest power bolt in your inventory. I can't remember if it does the same thing with Arrows, but I carry only two types of those and enough quantity that I don't run out.

yeah the game automatically equips the weakest arrow/bolt in your inventory when you run out. So i dont really know what to say, i guess you just gotta do em all manually.