Thank you Charlie for your welcome and excellent advice. I'll search through the Garages thread and also seek out an Alfa specialist.
I had a diagnosis done on Monday at a local Fiat dealer and the result came back as needing a new electronic solenoid unit (code PO60C) - can't fix for at least 4 weeks and may need car for a few days as the team on duty are not experienced with daulogics. The car has had a series of transmission issues over past couple of years with the previous owner. In 2014 they had to replace the gearbox activator unit, and the selespeed control unit. Then in July 2015 they replaced the solenoid and control module. Seems a bit extreme to have so many things replaced in such a short time period and to now need a new solenoid again. The dealership also was not confident that the solenoid replacement would fix the problem - losing its gear while driving or idling "gear unavailable. check transmission". I am hoping to find someone who has more experience with the dualogics and will investigate a bit further than just the code read-out.