You must open in your NAT the port thats used by de STATS.MOD (stats.conf)
I don't know what NAT you use, so read your NAT Manual for that
And yes, you can send the stats db's/pages trou FTP, only then you need an tfp script, that send the files over to your other ftp site...
I'm behinde a NAT (Sygate 4.5) too, and i can use live stats aslong the ports are open on the NAT, pointing to the internal LAN IP where the bot is running.
Regards,
TeDDyBeeR