This may show you how to use a Netgear router as a modem only:
how to use DG834 as simple ADSL Modem - NETGEAR Forums
Then wire the other Airport Extreme router in by ethernet -- see how to set that up as a wireless access point from an Apple forum, I suggest.
If no joy try posting your query on netgear.com user forum as one of the moderators there (jmizoguchi) uses Apple stuff, though you may have to tell him which Netgear retail model the V2 Sky router is equivalent to.