Change formula to fit an array but keep getting error messages

How do i change this formula to fit an entire column instead of just a single cell


Private Sub Worksheet_Change(ByVal Target As Range)
Dim xRg As Range
On Error Resume Next
If Target.Cells.Count > 1 Then Exit Sub
Set xRg = Intersect(Range("D7"), Target)
If xRg Is Nothing Then Exit Sub
If IsNumeric(Target.Value) And Target.Value > 200 Then
Call SendAutoEmail

Hi
you have posted in the wrong forum.
This should go to the VBA forum
I have reported it so it can be changed by a mod or admin
Cheers

PS please wrap code with code tags in the future