If there is an option in the ring that you don't want the user to see why not just exclude it from the ring (you can set the options programmatically by wiring an array of option names to the Strings property of the control) and make the code that interprets what selection has been done aware of what the currently available options are (if you e.g. have cases for each selection keep the strings array in a shift register and wire the array together with the value of the ring to a index array function...then use the text string as input to the case and have cases for each possible string, that way you can define all the cases but they don't have to correspond to a specific ring value)?
If you really want the option to be there but invisible set the string property
with that cell of the strings array to a blank.
