There are plenty of adapters that attempt to provide the kind of connection you need. Will adapter X work with hub Y? Impossible to predict. USB hubs are supposed to be invisible to devices (aside from the loss of speed when the port is shared) but some manufacturers are sloppy about that.
And that's not even your biggest problem. You'll need software to send printer commands over your serial channel. If it's a Postscript printer, you might find some open source software to do the job. If it uses a proprietary printer language, forget about it. The manufacturer has certainly stopped supporting the printer long ago, so even if you can download the software, getting it to run on W8 would be a royal pain.
Does the printer have some functionality that you can't replace cheaply? If not, the smart thing to do is simply buy a new printer.