Seriously if you are looking to mod a dell mobo of some kind to work with a standard power/reset switch, eh, good luck. I've tried with a few and got as far as getting one to power on but ran into alot more problems when it came to getting it to reboot and save bios settings.
I've been all over dells website as well. This is information they do not want you to have....lol but I bet you already know that. Good luck!