I figured out what I was doing wrong with the format of the dynamic variable. It should have been this:
set %final [ % $+ [ var $+ [ $calc(%uu +1) ] ] ]

Now I have all my data in the combo drop-down box when I init the dialog however the drop down part of the combo does not work. I know I need to add an "on sclick" event so it will act like a real drop down when I go to select one of the items in the list. What is the proper sclick format to make the box a true dropdown? Thanks.