Private Sub Document_ContentControlOnExit(ByVal CCtrl As ContentControl, Cancel As Boolean)
Dim StrNm As String
Select Case CCtrl.Title
  Case "Check1": StrNm = "C:\Temp\MyWorkbook1.xls"
  Case "Check2": StrNm = "C:\Temp\MyWorkbook2.xls"
  Case "Check3": StrNm = "C:\Temp\MyWorkbook3.xls"
  Case "Check4": StrNm = "C:\Temp\MyWorkbook4.xls"
  Case Else: Exit Sub
End Select
Dim xlApp As New Excel.Application
With xlApp
  .Visible = True
  .Workbooks.Open (StrNm)
  .Activate
End With
End Sub