Limiting A Macro To One Column

I have this code that applies an Alt-Enter command following text being entered in a range named "ActivityRange". ActivityRange is only one row currently, but I have another macro that inserts a row into that range. This code works to add an Alt-Enter after text typed into a cell, but it does it for every cell in the row. I want it to only apply to column "C" and not any values in other Rows. In other words, only apply this command if values are entered into column "C", of the range "ActivityRange".

Anyone know how to alter the code below to accomplish this?

Private Sub Worksheet_Change(ByVal Target As Range)
Dim Cell As Range
If Application.Intersect(Target, Range("ActivityRange")) Is Nothing Then Exit Sub
Application.EnableEvents = False
For Each Cell In Range("ActivityRange")
If Len(Cell.Value) > 0 Then Cell.Value = Cell.Value & Chr(10)
Next Cell
Application.EnableEvents = True
End Sub