Referencing A Gridview Template Field

Hi
I just created a template field within a gridview so that I could add a validation control. This is the first time I have done this so I wasn't familiar with the process. Prior to making the change, I had the following code to grab the contents of the gridview field (the one that was later changed to a template field) and use it as part of a download filename...
Response.AddHeader("content-disposition", "attachment; filename=" & ("Job " + Me.txtJob.Text) & " - " & Me.gvScannedDocs.SelectedRow.Cells(1).Text & "." & extension) Since I changed the field to a template field, the above code now returns a NULL value. I did some research and it looks like I need to use findcontrol to get the value of the template field. I came up with this, but it's not working...
Dim ScanRef As String = DirectCast(gvScannedDocs.SelectedR ...