You can try this
query=LVGSTN_ADD:"WHERE L_NAME LIKE 'A%'"
I had tried that this evening and it didn't work. It returned zero rows when there should have been over 1700.
I can't believe a process that seems so simple is incredibly hard when there is no accurate documentation explaining this stuff.
Thanks for your help anyway.
I found the problem. I substituted that table for another and it worked. When I compared both tables I saw that the one I was using was an EXTERNAL TABLE. Evidently oracle can't operate on that type. I simply forgot all about that table and its source.
Now I can put my lead pipe away and go to sleep.