If you want to open the message in Outlook, then you need to use the Outlook Object Model. Something along the lines:
set App = CreateObject("Outlook.Application")
set NS = App.GetNamespace("MAPI")
NS.Logon
set email = App.CreateItem(0)
With email
.To = "the_reciever@company2.com"
.Subject = "Great e-mail"
.HTMLBody = Your HTML text"
.Attachments.Add("c:\temp\Cute_kitty.jpg")
.Display
End With