Hi Colin:
if I am correctly assuming that you have a column named 'Priority' in your 'Open Work' worksheet you could place the following event handler into the VBA module associated with your 'Open Work' worksheet and give it a try (after you adjusted the constant PRIORITY_COLUMN to your situation):
Const PRIORITY_COLUMN As String = "B"
Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Column <> Columns(PRIORITY_COLUMN).Column Then Exit Sub
If Target.Value = 4 Then
Rows(Target.Row).Copy Worksheets("Completed Work").Range("A" & Rows.Count).End(xlUp).Offset(1)
Rows(Target.Row).Delete Shift:=xlUp
End If
End Sub
Hope this helped,
Rolf Jaeger
SoarentComputing
http://soarentcomputing.com/SoarentComputing/ExcelSolutions.htm