Find or Remove Duplicates in Columns

Hello.

I have following sheet:
Data from A1: BU1644

I need to check, if in A1:BU1 are any duplicate words.
All the formulas I found deal with finding duplicates downward (like A1:A1000).
Have not seen any formula which works across (from left to right)

Is there an easy way in Excel 2010 either to tag/ and -or remove the duplicate which I could apply and then just copy downward?
The formula must work from left to right, because many words repeat downward.

Thank you in advance for any suggestion.

I was considering that too, But 1644 rows? would need a lot of space.