Hi Sylvia,
I followed the link you gave me but could see how to post anything there. Always got the message that I am not allowed to create or edit content, so I gave up on that!
Anyway, overnight I have identified the pin and if it is appropriate, I can post back here a summary on using the Custom Solutions Header SMI_SCI_GPIO pin as an interrupt source with the Intel drivers and Microsoft GPIO framework on Windows 8.1 Embedded OS, including the information and changes required to the ACPI ASL to disable the current behaviour, and add the behaviour you need to enable the changed function (still getting the facts together on this part at the moment).
Thanks,
Mark