Selection.Count overflow when selecting all cells - vba

Question

In Excel 2007 I want to prompt a message when a cell (L2) is clicked on. I have a piece of code that works but the problem is that when I select all the cells in the sheet with Ctrl+A I get error number 06: overflow on the line If Selection.Count = 1 Then
Mandatory VBA code:
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Selection.Count = 1 Then
If Not Intersect(Target, Range("L2")) Is Nothing Then
MsgBox "ACTION!"
End If
End If
End Sub

Answer 1

Easily fixed:
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Selection.CountLarge = 1 Then
If Not Intersect(Target, Range("L2")) Is Nothing Then
MsgBox "ACTION!"
End If
End If
End Sub

Answer 2

Try this:
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If InStr(1, CStr(Target.Address), ":") < 1 Then
If Selection.Count = 1 Then
If Not Intersect(Target, Range("L2")) Is Nothing Then
MsgBox "ACTION!"
End If
End If
End If
End Sub

Answer 3

You must change your code as follows. No Error-Traps needed:
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Selection.Area.Count = 1 Then
If Not Intersect(Target, Range("L2")) Is Nothing Then
MsgBox "ACTION!"
End If
End If
End Sub

Answer 4

If you had 64-bit Excel I would tell you to use CountLarge instead of Count. Excel 2007 only comes in the 32-bit variety so that's not an option for you.
Your problem is that Range.Count returns a Long variable and throws an error if the number of cells is greater than a Long can store.
To get around this, you can do the following:
Use a Decimal data type stored inside a Variant. The combination can count more than the 1,048,576 rows x 16,384 columns of cells in an Excel worksheet.
Count the cells one column at a time to avoid the error with Range.Count.
I wrote a function that does that. Save this function in a regular code module (not a Worksheet or Workbook module) and use it like this:
If CountLarge32(Selection) = 1 Then
Here's the actual function:
Public Function CountLarge32(ByVal rangeOrSelection As Variant) As Variant
Dim target As Excel.Range
On Error Resume Next
Set target = rangeOrSelection
On Error GoTo 0
Dim cnt As Variant
Dim iColumn As Excel.Range
If Not target Is Nothing Then ' parameter -IS- a valid Range
' Use Range.Count on one column at a time to avoid the overflow error
' if counting higher than the limit of the Long data type.
For Each iColumn In target.Columns
cnt = CDec(cnt + iColumn.Cells.Count)
Next iColumn
CountLarge32 = cnt
End If
End Function
This function also avoids the error that occurs if Select is an object (e.g. button, shape, chart, etc.) instead of a cell.