Verboten,
This might be of help to you, go to my website:
http://webpages.charter.net/pminmo/cncelectronics.htm
Looks at the 3 or 4 axis interface board. This is the link for the document:
http://members.tripod.com/pminmo/4axisBOBdata.pdf
The aux1 driver is specifically for driving a relay. It will work with a ssr or mechanical relay. By connecting your relay between the x5-1 pin and x5-2 pin you would be able to switch your relay. All you really need is a npn transistor and a resistor.
http://www.beyondlogic.org/spp/parallel.htm Is an excellent primer on the parallel port as well as
http://www.hut.fi/Misc/Electronics/c.../lptpower.html
Phil