First, Forgive me, it’s been a long time since I’ve dealt with DOS drivers. But, if I recall correctly you’ll need a DOS print driver for the printer to print to it loaded.
If the printer doesn’t have a DOS print driver, I’m assuming it’s a network printer and you already have network card drivers and some sort of Network “Stack” loaded in DOS (Novell, lantastics, Microsoft Client for Networks, etc). If this is the case, try printing to the printer with the generic text printer driver. You’ll only be able to print text– but that may fit the bill.
The gist is, if the manufacturer doesn’t offer a DOS driver, you’ll need to try other DOS drivers that are similar an your config.sys and autoexec.bat.