Las mismas que para batch ...

set objshell = createobject("wscript.shell")
user = objshell.expandenvironmentstrings("%USERNAME%")
Msgbox "Hola " & user

Otra manera de conseguir algunas carpetas de sistema ...

set objfso = createobject("scripting.filesystemobject")
set windows = objfso.getspecialfolder(0)
set system = objfso.getspecialfolder(1)
set temp = objfso.getspecialfolder(2)
Msgbox windows.path
Msgbox system.path
Msgbox temp.path

Por último, algunas carpetas especiales de win ...

set objshell = createobject("wscript.shell")
Escritorio = objshell.specialfolders("Desktop")
Msgbox Escritorio

:http://msdn.microsoft.com/en-us/library/0ea7b5xe%28VS.85%29.aspx

Saludos