Hi Alex, 

here you get the needed infomations: 

I use the same hardware like the timing software . 
Your software uses the 'status pins'. My driver for the LEDs is connected to the 
'data pins' (the port address is 888, this means offset 0). 
I connect the 1st LED with DATA1 on PIN 3 (Dsub25, Parallel Port). 
The 2nd LED is on DATA2 on PIN 4, 3rd is on DATA3 on PIN 5, 4th is on DATA4 on PIN 6 
and the 5th is on DATA5 on PIN 7. The ground I need for the opposite current is connect to PIN 20. 
Between the Dsub25 and the LEDs there's a 100 OHM -1/8 W resistor working. For the LEDs I install 5 mm LED in red (default LED) . These
lights are build into a bridge in front of the starting line. The cabling is build with  a 8-wire copper-cable using in the networking area (you can also
use a small telefon cable, available in every computer shop). 
Both cables (one from the box of timing hardware, one from the bridge) I've connected to one 
Dsub25 as a Y-Cable. 
For the track power project I want to use DATA7 (PIN9) to drive a simple relais circuit selling by 
Conrad Electronics (#194565). This one need 3 - 30V control power to activate the main track power from 8 - 35 V with a max. of 4 A. I think
that is enough to realize this feature on hometracks. 

If I have tested it I will inform you about this gimmick. (til now my friends don't stop at the end of the races). I hope I can mail you a few pictures
of this building).