After further testing, I found how to use the NO CONFIRMATION FOR ONE :
PICK FROM queryBOxyz
NO CONFIRMATION FOR ONE
This will work as expected.
My previous error was due to writing PICK FROM queryBOxyz
WHERE BOxyz.Name=?Name NO CONFIRMATION FOR ONE and the configuration tool accepting this formulation... but error in operation mode.
Anyway, there is still a possible improvement to implement :
if no matching is found then display ALL instances instead of none !
That would avoid to have to start the process again from the menu (mouse/keyboard flip-flop).
Thanks