Converting the programs depends on
what platform you want to run the programs on;
how much of the Epson command set you depended on.
If you were doing fancy formatting relying on fixed width fonts and tabbing, that kind of formatting has mostly gone away. But if you're just doing bold and maybe centring, then outputting to HTML could be an option. The Epson's bold on/off could easily be replicated with HTML's <strong> … </strong> markup, for example.
If you're looking for a converter, epsonps is a basic Epson to PostScript filter. While it's limited it does have the advantage of being developed while dot-matrix printers were a thing, so it makes an attempt to handle most input gracefully.