I hate to even utter the words (consonants?) here, but for this case, tcl has a better solution than perl.

Have a look at the man page for tcl3270. Very comprehensive, including several 327x emulations, IND$ file transfers, etc, etc.

Pointers to tcl3270, and other 3270 resources are here.

Also, as others have already mentioned, newer versions of MVS include a POSIX facility, and most shops that have TCP/IP on the mainframe will have enabled an ftp server.