The following should do it (no need for MPEX):

!JOB RUNIT,GROUP.ACCOUNT
!file loadfile=ftpxfer;dev=lp,1
!RUN PROGNAME.GROUP.ACCOUNT
!xeq loadspid "FTPXFER" _spoolfile
!echo open 999.999.999.999   >gpftpin
!echo user name pswd        >>gpftpin
!echo put !_spoolfile Output.txt >>gpftpin
!echo quit                  >>gpftpin
!FTP <gpftpin
!EOJ


Where 'loadspid' would be the following command file:

parm banner_name  filename="_spool_fname"
setvar _banner UPS("!banner_name")
setvar _currjob "#!hpjobtype!hpjobnum"
listspf o@;seleq=[jobnum=!_currjob and filedes=!_banner] >$newpass
print $oldpass;start=4;end=4;out=$newpass
input _spid_text < $oldpass
setvar !filename RTRIM(LTRIM(LFT(_spid_text,10) - "#"))+".out.hpspool"
deletevar _banner, _currjob, _spid_text

Regards
Paul Christidis