I'd like to assign Login.aspx its own skin, or at the very least, its own container to wrap the "Log In" module.

If you're curious why, I'd like to do this so that logging in can only happen from inside our intranet.  Inside the skin, I'll check the alias with asp using something like (and this is rudimentary...I'd need to look up some asp, as I'm more of a php guy):

<%If (PortalSettings.PortalAlias.HTTPAlias=="localhost")%>
(and here I'd put the pane div where the container's been placed)
<%End If%>

Also, while I'm here, is there any sort of extended reference material for those tags like <%PortalSettings.PortalAlias.HTTPAlias%>?  What are these things called?

Thanks!