behind two routers can I file share?

[Gh0ce]

well, to put it simply: I am behind 2 routers then to the internet. What I want to do is to share files with someone on router 1. I am on router 2. router 1 has 2 pc's plugged into LAN and router 2 plugged into LAN and the modem plugged into WAN and 1 free LAN port. Router 2 is wireless and has nothing plugged into LAN, but has router 1 plugged into WAN. (now I hope that made sense). What I want to do is to be able to share files with computers plugged into router 1 when I am connected to router 2 (wirelessly...) router 1 is a wired-only router, router 2 is a wireless router.
Is this possible without installing VPN software such as hamachi?
both pc's running windows XP pro.
Is it possible to share files using the windows file and printer sharing protocols?
thanks a bunch
The Gh0ce_>0 (thinks of himself as a smart guy in terms of computers, but this is baffling him...)