This is what I do (both subforms have the same number of fields and I use the same naming convention):
Code:
Private Sub Field1_Enter()
On Error Resume Next
Me.Parent.Form.sfrmlBCS_Profiles_Import.Form.Controls("Field1").SetFocus
Me.Field1.SetFocus
End Sub
So I have similar code for all controls in the subforms (you could also create a macro and use that in the OnEnter events to make it easier to implement).