MMpostcode is located in Map Utilities (alongside the Map Data).
You may need to re-import the postcode data occasionally, but it should be retained from one session to the next.
The data is kept in Map Data > Code-Point Open > data
Choose from the UK data set CSV or EH Post Codes.
Enter the postcode and click Go To.
Post codes are represented as Markers, which can be saved as a .dra file (Menu > Markers > Save markers as … ).