Well I went ahead and wrote a little launcher for the ftp server. Assumes you have it installed on storage card but you can change the path easy enough.
REMOVE the .TXT extension, then change [YOURHOST] and save onto the phone.. ie - hostname=myphone.dyndns.org
The 1st time you run this IE will ask for your dyndns username/password, make sure you save them. From then on it will auto authenticate then launch the ftpserver.
Can't find a way to make mortscript authenticate by itself so thats why ie has to be launched instead.
Code:
Run( "\Windows\iexplore.exe", "http://members.dyndns.org/nic/update?hostname=[YOURHOST]" )
Sleep(3000)
Run( "\Storage Card\Program Files\Communication\ftp server\mftpd.exe")
Exit
***Remember to remove the .TXT