Try a VBScript Custom Action stored in the custom action (Type38) with the following script
Option Explicit
Dim objIExplorer, bIsObject
Set objIExplorer = CreateObject("internetexplorer.application")
bIsObject = IsObject (objIExplorer)
If (bIsObject <> True) Then
MsgBox "Error creating IE object", 0
Else
objIExplorer.Visible = True
objIExplorer.navigate "http://www.installshield.com"
End If
Set objIExplorer = Nothing