Macro that controlls duplicate values

[Emece]

I have a sheet with some values, and other sheet with a
combo box that refers to that values. The values can be
repeated, I want a macro that controlls if the value is
repeated then show it only once in the combo box.

Thank you.

 

[Tom Ogilvy]

http://j-walk.com/ss/excel/tips/tip47.htm
Fill a listbox (combobox) with unique values

From John Walkenbach's site.