Set focus to original datagrid cell after handling data validation with column changing event

I wish to use data validation with a datagrid on a windows form, and when the data is invalid, throw up a message and select/set focus to the original cell in the datagrid in which an invalid entry was enterred.  The datagrid is on a windows form and I am using .NET Framework 1.1

So far I have done the following. As a test I don't allow for "aa" in a column called "Title"

    AddHandler MainDS.Tables("Images").ColumnChanging, AddressOf Me.MyColChanging

    Private Sub MyColChanging(ByVal sender As System.Object, ByVal e As System.Data.DataColumnChangeEventArgs)

        If Not IsDBNull(e.ProposedValue) Then       ' this was needed to allow for nulls

            If e.ProposedValue = "aa" Then
                MsgBox("Title should not equal " & e.ProposedValue)
                Throw New Exception("oops")

            End If

        End If

    End Sub

This will show a message and satisfactorily stop "aa" from being added to the "Title" column. However when you move from the cell, whether with mouse or keyboard,  try as I might, I cannot find a way to select the original cell.

Incidentally I have no idea how the "Throw New Exception" works.  When I tried to use an "On Error GoTo" in the handling routine the code in the on error section would run OK, but the invalid data was allowed in the original cell.  Any comments on this would be appreciated also.