Changing cell colour if calculated value in the cell changes based

[AxiaoNailo]

I have 2 worksheets in the same spreadsheet and 2nd worksheet dates are based on 1st worksheet with various vlookups. Now, I have known how to change the cell color if the calculated value in the cell changes:

Private Sub Worksheet_Change(ByVal Target As Range)
Target.Interior.Color = RGB(255, 0, 0)
Worksheets("Name_Of_2nd_Worksheet").Range(Target.Address()).Interior.Color = RGB(255, 0, 0)
End Sub

but 2nd cell data are not in the same cells as the cells on the first worksheet. For example, When I modify A1 in worksheet 1, I use the vlookup function in worksheet 2 to track the data changes in cell C3 of A1. However, if I use the above code, it is still A1（in 2nd Worksheet）that changes color. What can I do to change the color of cell C3 in worksheet 2 when I modify cell A1?

In addition, because the data changes irregularly, I think I should not be able to use a conditional format. For example, the data will change from 7300 to 9600, or from 8000 to 6500. If I want to use a conditional format, the data change should need a change rule.

It is possible? Thanks!

 

[Zot]

If you are having the change event code in worksheet then when you change A1
1) Sheet1 range A1 will change to Red
2) SHeet2 range A1 will change to Red too

This is because Target refers to changed cell A1 of Sheet1. The target address in the line below is the Sheet1 target address:
Worksheets("Name_Of_2nd_Worksheet").Range(Target.Address()).Interior.Color = RGB(255, 0, 0)

If you replace the bold above with "C3" then Sheet2 range C3 will be Red.

Not cleat how your lookup looks like and not really understand what you are trying to do.