Enable or disable "Possible Entries" matchcode property in GUI Dynpro with ABAP code

Hi everyone

I request your help because I have a requirement to enable the match code property for a custom field in a GUI Dynpro (set the "Possible Entries key" property set to "1 - show at selection") but only when the transaction meet at specific criteria, otherwise the match code property but remain disabled (set "Possible Entries key" property to initial) to type manually the field value, this criteria must be set inside the selection screen, so I need to setup the code inside PBO section.

I was looking similar issues in several pages, included here, but I had no luck.

Can you help me giving an idea of how to accomplish this?

Thanks in advance

Lorenzo Martín Olmos