What you are looking for can be achieved by adding only the columns that you want to show to the Portal users into "List of schema fields for portal access" lookup. As a result those fields won't be available on any of the dropdown list.
What you are looking for can be achieved by adding only the columns that you want to show to the Portal users into "List of schema fields for portal access" lookup. As a result those fields won't be available on any of the dropdown list.
You cannot add any new columns here as it's a base object and located in a base locked system package.
If you want to simply add more options to the account Industries lookup, you can do it directly in the Lookup section (System Designer - Lookups - Industries) :
We have already registered the issue for our R&D team to fix this functionality in further releases. I will assign your case to this project in order to increase its priority.
To solve this issue we recommend you generate the source code and compile the system.