I have the need to determine if a specific range of cells
have values resulting from an autofill action.

Example:
If Range("C7").Value = "Jan", and AutoFill was used to
make C7-K7 = "Jan","Feb","Mar",etc

How can I tell programmatically that AutoFill was used to
perform this action?

I can easily do this:

ThisWorkSheet = Excel.Application.ActiveSheet

With ThisWorkSheet
If .Range("C7").Value = "Jan" _
And .Range("D7").Value = "Feb" _
And .Range("E7").Value = "Mar" _
And .Range("F7").Value = "Apr" _
And .Range("G7").Value = "May" _
And .Range("H7").Value = "Jun" _
And .Range("I7").Value = "Jul" _
And .Range("J7").Value = "Aug" _
And .Range("K7").Value = "Sep" Then
MsgBox("Cool")
Else
MsgBox("Not Cool")
End If
End With

But, that doesn't reach my goal of finding out if
AutoFill was used.

Thoughts?