Here is two examples.
The Buttons do not move but the titles are ordered.
Example 1, Sorts the external data and then applies it to the buttons.
SortButtons1.hype.zip (25.6 KB)
Example 2, takes the current Button titles into an array, sorts the array and re applies to the buttons.
SortButtons2.hype.zip (17.0 KB)
It would be a good idea for you to post your hype doc so we can see it's workings to give a better answer.