Macro-Compare two columns and highlight rows with duplicates

[ffionnah]

Hi all,
I have been searching high and low for a macro to compare 2 columns within a range (possibly selected) and highlight the rows that have duplicate values.

The columns would be:
Column 1 = AO
Column 2 = AS

Within the range selected, those 2 columns will always be the 2 being compared. If there is a way to make the range from the Do Until (Specifically column AO) ActiveCell.Value = Empty, that would be perfect also.

There are values in AO based on a macro I have that identifies unique names and distributes a unique number for those names. For instance, 3 rows in that selection may all be given the unique number of "1" because the name is the same within the range/criteria.

A basic example of this is:

Name: Unique #:
ABC123 1
ABF124 2
ABC123 1
ABG125 3
ABC123 1
ABF124 2


With that being said, I need AO to vlookup to AS, find duplicates and highlight the entire row with the duplicate.


I cannot use conditional formatting because there are already duplicates within AO, as shown above.

 

[ffionnah]

Help!

Thank you

 

[ffionnah]

I thought I posted but i do not see it; After much digging, I threw a few things together

This macro is only highlighting the first row, what am I doing wrong?!

 Sub HighlightMatch()Dim Rng As Range
Dim WorkRng As Range
On Error Resume Next
Set WorkRng = Application.Selection
Set WorkRng = Application.InputBox("Range", xTitleId, WorkRng.Address, Type:=8)
Application.ScreenUpdating = False
For Each cell In WorkRng
    If WorkRng.Cells(i, 43).Value = WorkRng.Cells(i, 44).Value Then
        WorkRng.Cells(i, 44).EntireRow.Interior.Color = RGB(255, 255, 0)
    End If
Next
Application.ScreenUpdating = True
End Sub