DOBT is a free LISP utility by CAD Studio - you can use it to change the draworder of AutoCAD entities by their object type and by their layers.
You can define the order in the definition file - it sets all processed object types and layers. Using this definition you can e.g. - with a single command - move all your texts and dimensions on top of all hatches, AEC rooms below AEC walls and curtain walls, etc. Or you can define that the contents of layer BRIDGES will be drawn above the contents of the layers WATER*.
Entity types and layers are listed in the DOBT.TAB control file (see Readme). Example:
You can download the DOBT utility from www.cadstudio.cz/download