I had misread your initial post thinking that you were trying to eliminate duplicates. Instead you are saying that only certain UIs are valid for import. The only way I can think to do that is again to have a scratch table to import into and then use a filtered version of that to copy across to another table for just the valid UIs. That step to copy across the valid ones could be a single button click that would import the valid ones and say delete the records in the scratch file.
But I can't think of a native way to import and have invalid ones get scrubbed out during the import process, all as one step. But my suggestion would be pretty close.
1. Raw import to a scratch file
2. Push a button.
