How about this

Sub test()
Dim hhh, n, c, s1, nr(), g5, h

    hhh = "yes1"
    n = 10
    c = 5
    s1 = 15
    
    Select Case hhh
        Case "no"
        Case "yes"
            For h = 1 To s1
                ReDim Preserve nr(1 To s1)
                nr(h) = n - c
            Next h
    End Select
    
    If Not Not nr Then
    
        g5 = Application.Average(nr)
        Debug.Print Join(nr, " ")
        Debug.Print g5
    End If
End Sub