Creating custom select menu

[Cupara]

Ok I want to use a PHP Callback on an admin setting that will allow me to pull all prefix groups then have them displayed in a drop down list. The problem I have ran into is that no matter what method I attempt to use I get the same result, error after error, or it will display the id of each prefix group and the display order number of each group as its own select option.

What I want to do is set each value of the formatParam without having to edit the select style at all.

Anyone have a method that they can give me an example for?