How to disable a function key in a display file without using indicator to deactivate its command function?
===

Suppose in a display file DDS CF20 has been specifies to make F20 available. Now I want to disable this function when certain condition is met in a RPG program. As this program has already used up all the general purpose indicators In01-IN99, using an indicator to deactivate CF20 keyword in the display file is not an option. Is there any other alternative to achieve this?