Get Around Excel's Three-Criteria Limit for Conditional Formatting

You can use VBA to conditional formatting to use more than three criteria on your data. In fact, you can use the code to apply virtually an unlimited number of criteria.

Excel has a very useful feature named conditional formatting (described in Tutorial 2). You can find it by selecting Format Conditional Formatting... on the worksheet menu bar. Conditional formatting enables you to format a cell based on its content. For example, you can change to a red background all cells whose value is greater than 5 but less than 10. Although this is handy, Excel supports only up to three conditions, which sometimes is not enough.

If you want to set more than three conditions, you can use Excel VBA code that is fired automatically whenever a user changes a specified range. To see how this works, say you want to have six separate conditions in the range A1:A10 on a particular worksheet. Set up some data such as that shown in Figure 7-9.

Figure 7-9. Data setup for conditional formatting experiment

Save your workbook, then activate the worksheet, right-click its Sheet Name tab, select View Code, and enter the following code:

Private Sub Worksheet_Change(ByVal Target As Range)



Dim icolor As Integer

If Not Intersect(Target, Range("A1:A10")) is Nothing Then

 Select Case Target

  Case 1 To 5

     icolor = 6

  Case 6 To 10

     icolor = 12

  Case 11 To 15

     icolor = 7

  Case 16 To 20

     icolor = 53

  Case 21 To 25

     icolor = 15

  Case 26 To 30

     icolor = 42

  Case Else

   'Whatever

End Select

  Target.Interior.ColorIndex = icolor

End If



End Sub

Close the window to get back to your worksheet. Your results should look like Figure 7-10.

Figure 7-10. What data should look like once the code is entered

The background color of each cell should have changed based on the number passed to the variable icolor, which in turn passes this number to Target.Interior.ColorIndex. The number that is passed is determined by the line Case x To x. For example, if you enter the number 22 in any cell within the range A1:A10, the number 15 is passed to icolor, and then icolor (now having a value of 15) is passed to Target.Interior.ColorIndex, making the cell gray. Target is always the cell that changed and, thus, fired the code.