You are correct in that it doesn't have "absolute" rotation, as technically AC3D doesn't have rotation at all. Once an object is rotated in AC3D, it modifies the vertices themselves and that is the new, permanent position. Rotation is a pretty common feature request. (Probably wouldn't hurt to bump the thread in "suggestions" or send a feature request to support.) I'm keeping my fingers crossed for this one myself.
What are you trying to do? Maybe I can help.