musoware forums

Quite a few years ago when I started using Muso I populated a custom field with some data I thought of interest. Last year I decided to use a new field which will have the same type of data plus some more, if available and stopped using the former one. I now wonder if there is some way within Muso to re-import all albums and copy the old data to the new field if that new custom field is blank, otherwise skip the action copy for that entry if not blank.
I believe it could easily be done with SQL but I confess I have no experience.
Any help would be appreciated.