send more than 8 bits with parallel port

We're using a parallel port for motion control. We're building the
hardware logic for the device we're going to control, and want to be
able to send a packet containing 2 bytes of information, and let the
circuit we build translate it and drive our device.
I know that parallel port was designed with a standard for printers,
using a 1 byte data regisiter. What I want to know is how to hack it
so that I can use more than pins 2-9 to output data from our computer.
The control register has pins 1, 14, 16, 17. I take it that i can set
whatever I want to these (TTL), and on the device end, translate it
however I choose. So i need 4 more pins from something.
I know that pins 18-25 are ground. I think that makes them out of the
question, though if anyone knows how I could use some of them to
transmit data I'd be interested.
The info i have on status register says its read only, and that data
written there is ignored. What ignores it, the computer or the
printer? Is there a way to get around it?

thanks
James

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