ok this is my first post but im pretty sure this should help you
download wget (
*nix version |
windows version )
its a command line utility but it should work
for example
wget -r --accept=gif,jpg,htm
ftp://user@pass:myserver.com
would download all files from your server that hat the extensions .gif .jpg and .htm
i hope thats what youre searching for
have a nice day...