You could define an array of panels.
Dim Panel1, Panel2, Panel3, Panel4, Panel5, Panel6, Panel7, Panel8, Panel9, Panel10, Panel11, Panel12, Panel13, Panel14, Panel15, Panel16 As Panel
Dim Panels(16) As Panel
Panels = Array As Panel (Panel1, Panel2, Panel3, Panel4, Panel5, Panel6, Panel7, Panel8, Panel9, Panel10, Panel11, Panel12, Panel13, Panel14, Panel15, Panel16)
Then you know that Panels(8) to Panels(11) are the panels in the 3rd row.