IIC, I2C on GPIO 21 & 25

I am trying to figure out the best way to integrate the fastrack supreme 20 with my application. The best option would be to drive some chips via I2C. I have found in these forums mentions of a software defined I2C bus, as opposed to the hardware one available through an IESM expansion board. If I2C was available through the Power connector IOs GPIO 21 & 25, it would allow significant savings on the IESM board.
So is it possible to setup I2C coms via the power connector.
I am using rtos R72_00_full_fsu002 and openAT software suite 2.10.
Thanks for your help, and I hope this will be helpful to others as well,
Best regards,