Run macro when cell vaule in a range changes

[Tom-Ronny]

How could one start a macro when a cell value within a range is updated/changed?

The challenge is that i have a fairly big matrix of 800 rows times 365 collumns which contain a macro to check column by column for double entry and change the background of the cell if it exist. This is way to heavy to have running non stop, so a better way would be to have the macro run for a spesific column whenever a value in that column is changed.


Anyone have a good idea to how this could be solved? and maybe a code that would handle this variation? I have found many examples of how to do this when a single cell is cahnged, but this would need to look at a given matrix instead.



Thanks for any help

 

[Sixthsense]

Use Conditional Formatting>>Format Only Unique Or duplicate Values Option

 

[Tom-Ronny]

Thanks Sixthsense, but the conditional formating is (as far as I feel) limited to smaller ranges. I have tried the conditional formating on this and it does not give me the options I need, much due to some challenges as I have pointed out in my other thread.

 

[Sixthsense]

Sorry I don't know how CF is failing in your case

 

[Teeroy]

Set the matrix area as a named range then use the Worksheet_Change event to look for an Intersect between the named range and the Target cell of the event. I.e. if you set then named range as "Test_Area" then the code (in the SHEET CODE Module, not a standard code module) would be:

Private Sub Worksheet_Change(ByVal Target As Range)
If Not Intersect(Range("Test_Area"), Target) Is Nothing Then
    MsgBox "I've changed in the Range" 'this is where you put your code
End If
End Sub