FTP via Airport Extreme

[Wilkin, Wayne (Mass)]

Setup:
Cable Modem/Airport Extreme/Netgear 8 port router
Computers:
1 Laptop/1 G4 733/1 dual 125
All computers and airport software are running X.3.4, all airport software
and firmware up to date.
2 G4's are plugged into the router, laptop is wireless.
The 733 is running as an FTP site only
The dual 125 is a regular desktop station.
The airports IP is 64.x.x.x
The G4's and laptop get their IP's from the basestation. 10.0.1.6, .7, .8
The .7 system is the FTP computer.
Problem:
I can access the FTP computer via FTP software but only within my own
network. If I try to access from outside my network, say from my work, no
dice. I know it has something to do with the setup on the Airport but can't
figure it out. Thanks in advance, Wayne.