I've modified (and tightened up) your code in order to add the functionality
you asked for... see if this does what you want:

Private Sub Worksheet_Change(ByVal Target As Range)
On Error GoTo ErrHandler:
If Target.Count = 1 And Not Application.Intersect( _
Me.Range("G7:P2041"), Target) Is Nothing Then
Application.EnableEvents = False
If IsNumeric(Target.Value) And InStr(Target.Value, ":") = 0 _
And Len(Target.Value) < 5 Then
Target.Value = Format$(Target.Value, "'00\:00")
Else
Target.Value = UCase$(Target.Value)
End If
End If
ErrHandler:
Application.EnableEvents = True
End Sub

Rick


"Patrick C. Simonds" wrote in message
...
I use the code below to force all text to be in upper case. Now I need to
ensure the the number entered in column Q is converted to a time format.
The time is always entered in the 24 hour format (18:45 = 6:45 pm, 0645 =
6:45 am) but the often forget the " : ". These cells are not used for
calculations, but they still need to be in the proper format. so is there
any way to force 1845 to me converted to 18:45 or 645 to 06:45 while
ignoring a correctly entered number?


Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Cells.Count 1 Then
Exit Sub
End If
On Error GoTo ErrHandler:
If Not Application.Intersect(Me.Range("G7:P2041"), Target) Is Nothing
Then
If IsNumeric(Target.Value) = False Then
Application.EnableEvents = False
Target.Value = StrConv(Target.Text, vbUpperCase)
End If
Application.EnableEvents = True
End If

ErrHandler:
Application.EnableEvents = True
End Sub