If you have designs that need to be converted then why are you looking for a script? And, how will the script help? A script can be written that reads a flat file, which contains part numbers (?) and then searches and places parts into a schematic but not sure if this is what you are asking.
The process of selecting parts from Dxdatabook is slow and time consuming. If I can select them and place them in current sheet by list it would speed things up. It's for flat design yes. Hierarchical design will be done manually. Another advantage of selecting from a list will be there's no overtyping or selecting wrong parts as it is defined by an already existing list. If you don't want to draw a schematic but want to use the schematic to convert to expedition PCB there's another advantage. A placement file from old design can be used to import in expedition to place parts automatically on correct coordinates. From here you can convert to ODB output, redraw old PCB designs, etc.