Ring Item Change

How can I cahnge Ring item by keyboard input

For example

Ring Initial as follow

Item       Value

AA              1

BB              2

CC             3

DD             4

when i choose "BB",then i enter "EE"

Ring will change to

Item       Value

AA              1

EE              2

CC             3

DD             4

but everytime I click on Ring,always show the Item List,so that i can't change the value.

I've try "Prompt User",but it will popout a new window,

Thx for your reading, and sorry for my poor english