The printer configuration tool maintains /etc/printcap, print spool directories, and print filters. It is designed to use GhostScript ( gs), to convert PostScript files to a format understandable by your printer. Thus, you must print PostScript documents. You can use nenscript to convert plain text to PostScript.
Keep in mind that lpr prints to the lp printer (by default) and nenscript prints to the PostScript printer (by default). You will probably want lp to be one of your printer ``names''.
Needless to say, ghostscript and nenscript should be installed.