There is no elegant way to do this on Windows 2003 Server.
The following will add TCP ports 5500 to 5700 one at a time - run at the command line.
"FOR /L %I IN (5500,1,5700) DO netsh firewall add portopening TCP %I "Passive FTP"%I"
The inelegant way is to add port range, you can use the GUI to add that range to a defined port then export that registry entry and make changes to that .reg file and import it back.
Will update details at later time.