Seguendo il suggerimento di inserire una label con caption =
"www.miodominio.it"

codice:
' in testa alla form
Option Explicit
Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" (ByVal hwnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long

' Il codice del Click sulla label
Private Sub Label1_Click()
    Dim X As Long
    X = ShellExecute(Me.hwnd, "Open", Label1.Caption, 0&, 0&, 1)
End Sub
ciao,