Field to display all nets in layout and filter as I type

Hi, 

I want to create a field with dropdown menu that displays all net names in my layout and it should filter the net names as I type. leCreateNetField is working as I expected but its not allowing me to add any new net name that's not present in the list. 

So, I started using hiCreateComboField, which allows adding a new net name also. But I'm missing the filter option. Either I should completely type the net name or select one of the all net names displayed from drop down. Is there a way to add filter feature to hiCreateComboField? 

Thanks,

Prasad