There is yet another way to call an as400 program (or sumbit a batch program) via ftp.
Setup a batch file that runs "ftp <host> -s:scriptfile.ftp".

scriptfile.ftp

user
password
quote RCMD SBMJOB CMD(CALL PGM(pgmname)) JOB(jobname)

** Alternative way is creating a "24x7 script" type job that uses Telnet statements  to connect to your AS400 host and run this program via Telnet.