Funnily, I used to love such * programs in C. I wouldn't have answered this, but I couldn't stop trying this after a long time.
You can make a hut with something like this,
Dim inp As Integer = CInt(InputBox("Even Number > 4"))
Dim output(,) As String
ReDim output(inp - 1, inp)
For i As Integer = 1 To inp
If i = 1 Then
output(i - 1, inp / 2) = "*"
ElseIf i > 1 And inp / 2 - i + 1 > 0 Then
output(i - 1, inp / 2 - i + 1) = "*"
output(i - 1, inp / 2 + i - 1) = "*"
ElseIf inp / 2 - i + 1 = 0 Then
output(i - 1, inp / 2 - i + 1) = "*"
output(i - 1, inp / 2 - i + 2) = "*"
output(i - 1, inp / 2 + i - 2) = "*"
output(i - 1, inp / 2 + i - 1) = "*"
ElseIf inp / 2 - i + 1 < 0 Then
output(i - 1, 1) = "*"
output(i - 1, inp - 1) = "*"
If i = inp Then
output(i - 1, 2) = "*"
output(i - 1, inp - 2) = "*"
End If
End If
Next
and output like this
Dim opstring As String = ""
For i As Integer = 0 To output.GetLength(0) - 1
For j As Integer = 0 To output.GetLength(1) - 1
If output(i, j) = "" Then
opstring &= " "
Else
opstring &= "*"
End If
Next
opstring &= vbCrLf
Next