Paste the following to the worksheet's class module. Right click the
worksheet tab and select "View Code" to access the code module. Change the
cell reference ("$A$1") to suit and name of the spinner ("Spinner 1").

Option Explicit
Private Sub Worksheet_Change(ByVal Target As Range)
With Target
If .Address = "$A$1" Then
Me.Shapes("Spinner 1").ControlFormat.Max = .Value
End If
End With
End Sub