Well that is what JCL is for.
The DOS SNOBOL4+ environment from Catspaw implements something similar: you can assign files to a filehandle id (from 1 to 16) on the command line and just refer directly to the filehandle in your program. Of course, you can open a file by name from within your program if the old method is too clunky. :-)
Wade.
"Ah. One of the difficult questions."